The siddha deha can be revealed by Sri Krishna, the Holy Name, Sri Gurudeva and by the strength of one´s own bhakti.

Now, let us consider the revelation by Sri Gurudeva.

When testing a disciple’s natural inclinations, Gurudeva observes if he has the exact qualifications for serving in the śṛṅgāra-rasa, and informs him of his siddha-mañjarī-svarūpa (perfected form as a mañjarī) amongst Śrī Lalitā’s associates within Śrī Rādhā’s group. Then he will establish a mutual relationship between the sādhaka’s ekādaśa–bhāva and the sādhya (goal) of aṣṭa-kālīya-līlā. The name of the sādhaka’s siddha–deha, the form, qualities and service will be properly revealed.
(Bhaktivinoda Thakur, Śrī Harinama Cintamani)

The siddha deha is an expansion of the Supreme Lord. It is a manifestation of His inner potency or svarupa sakti and it is BESTOWED by Sri Krishna.

tvaṁ bhakti-yoga-paribhāvita-hṛt-saroja
āsse śrutekṣita-patho nanu nātha puṁsām
yad-yad-dhiyā ta urugāya vibhāvayanti
tat-tad-vapuḥ praṇayase sad-anugrahāya
(Srimad Bhagavatam 3.9.11)

“O Lord! You, who are approached by being heard about, seen and directly served, enter and remain in the lotus of your devotee’s hearts infused with bhakti-yoga.
Much praised Lord! By your mercy, you bestow to them spiritual bodies appropriate to the mood they cultivate during sādhana.”

Srila Viśvanātha Cakravartī Ṭhākura explains – te sādhaka-bhaktāḥ sva sva bhāvānurūpaṁ yad yad dhiyā bhāvayanti tat tad eva vapus teṣāṁ siddha dehaṁ praṇayase prakarṣeṇa tān prāpayasi aho te sva bhakta pāravaśyam iti bhāvaḥ –
“Or your devotees doing sādhana concentrate on their spiritual form according to their mood of love using their minds, and you have them attain (praṇayase) their spiritual bodies. You become dependent on your devotee.”

In fact, the siddha dehas for manjaris are actually expansions of Srimati Radhika.

vaikunthasya bhagavato jyotir-amsa-bhuta vaikuntha-loka-sobha-rupa ya ananta murtayas tatra vartante tasam ekaya saha muktasyaikasya murtir bhagavata kriyata iti vaikuntasya murtir iva murtir yesham ity uktam
(Priti Sandarbha 10)

“In the spiritual world, the Supreme Lord has unlimited spiritual forms. They all are expansions of Himself illuminating that world. With each one of those forms, the Lord enjoys pastimes with a single individual liberated soul.”

akara svabhava-bhede vraja-devi-gana
kaya-vyuha-rupa tanra rasera karana
( CC 1.1.79)

“The multitude of Vraja-gopis have various natures (svabhava). They are the forms of Her bodily expansions (kaya-vyuha-rupa) and Her instruments for creating rasa.”

Sri Krishna (or Srimati Radhika) will reveal this form to Sri Gurudev, then Sri Gurudev will realize and see this form and he will know his disciple.
In that way we can achieve our eternal form.
Everything is there – we only have to reach our target. We have our form there. Gurudev will reveal to us the information and the reality of this form. It is not speculation – it is not coming by his imagination.

Maybe Sri Gurudeva will give some things, and then, later, all other details will come by our meditation, by our performance, by our activities.
Because there are so many things, Gurudev may reveal some points or he can reveal all these details.
By his own sadhana, his bhajan, the sadhaka can see and finally realize all the other details of his svarupa.

In the spiritual world, the name and the one who owns the name are non-different.
Krishna´s name is not different from Him, Radhika´s name is not different from Her.
By meditation on Their names, Their forms will be revealed to us.

First is the name, then the qualities, then the form and the pastimes (nama, guna, rupa, lila).

This is also the recommended sequence Sri Jiva Goswamipad tells us to meditate upon. First we start with the name, then everything gradually unfolds (Bhakti Sandarbha).

Now, the siddha deha is an expansion of the Lord (or of Radhika) as written by Sri Jiva Goswamipad.

I received the name and the other information (ekadasa bhavas) from the lotus mouth of my Gurudeva to whom it was revealed by Krishna.

So, like mentioned, the name and the named are non-different in Goloka Vrindavana.

If I see the name of my siddha deha and if I meditate and remember and read and hear that name, the form of that particular siddha deha will reveal itself too.
There is no difference between my manjari-name and my manjari-form.
It starts right there.

If I meditate on my SIDDHA DEHA-qualities, on my complexion (form), dress, etc…this meditation purifies my impure mind and the purer the heart gets by sadhana-bhakti (hearing and chanting, etc…), the more this siddha deha will be revealed in my heart.
Each information, each revealed BHAVA has such enormous POWER.

siddha-rūpeṇaantaś-cintitābhīṣṭa-tat-sevopayogi-dehena
(in both the tikas of Srila Jiva Goswami and Srila Vishvanatha Cakravartipad Thakur to Bhakti Rasamrita Sindhu 1.2.295)

“In the siddha-form means in an internally conceived, desired body suitable for His service.”

siddha-rupena manas-cintita-svabhishta-tat-sevopayogi-dehena
(tika by Sri Mukunda Goswami to Bhakti Rasamrita Sindhu 1.2.295)

“In the siddha-form means in a mentally conceived, desired body suitable for His service.”

Artificial “imagining” will not suffice.

But not only does Sri Gurudeva reveal the siddha deha of the sadhaka. He will reveal the siddha dehas of the entire parivar.
And every morning, the sadhaka reads and memorizes this most precious information and this is even MORE purifying, consisting entirely of MERCY.

Srila Dhyanachandra writes:

sakhīnāṁ saṅginī-rūpām ātmānaṁ bhāvanā-mayīm |
ājñā-sevā-parākāṣṭhā-kṛpālaṅkāra-bhūṣitām |
tataś ca mañjarī-rūpān gurvādīn api saṁsmaret |
(DhPad 110)

“Being decorated with the ornaments of (1) her personal order (concerning her sevā), (2) her cherished desire for sevā, and (3) the mercy of the sakhīs, and deeply absorbed in the conception of herself as a companion (saṅginī) of the sakhīs, she shall meditate on her guru-varga in their mañjarī forms.”

atha yugala-mantroddhāro yathā sanat-kumāra-saṁhitāyām–
gopījana-vallabheti caraṇān iti ca kramāt |
śaraṇaṁ ca prapadye ca tata etat pada-dvayam
(DhPad 344)

“Concerning that dhyāna, before anything else, the sādhaka should perform smaraṇa of the mañjarī forms of his guru-praṇālī, beginning with his guru, then parama-guru, etc…
Then he shall meditate on Śrī Rādhikā, and after that Śrī Nandanandana.”

The descriptions of oneself, one’s gurus and the other manjaris are all learned from the guru. Whenever in doubt, the sadhaka ought not to venture into the realm of creative imagination, but rather consult a person acquainted with the realm of the lila.

manjaryo bahusah rupa-guna-sila-vayo ‘nvitah ||
nama-rupadi tat sarvam guru-dattam ca bhavayet |
tatra tatra sthita nityam bhajet sri-radhika-hari |
|bhavayan sadhako nityam sthitva krishna-priya-grihe |
tad ajna-palako bhutva kaleshv ashtasu sevate ||
(DhPad 107-109)

“One should meditate on the various forms, qualities, natures, blooming youth and so forth of the manjaris, as described by the guru. One should always stay with them, worshiping Sri Radhika and Hari. The practitioner shall stay in the home of Sri Radha, the beloved of Krishna, following their orders and rendering service throughout the eight phases of the day.”

As one learns of the characteristics of the manjaris from one’s guru, so one learns of one’s own manjari-svarupa from one’s guru. Indeed, the information we receive about our manjari-svarupa is given by the guru’s grace!

sarva-lakshana-sampanna bhava-havadi-bhushita |
guru-prasada-janani guru-rupa-priyanuga ||
(DhP 87)

“She has all pleasant characteristics and is adorned with feminine gestures that excite feelings of love. This form is revealed by the mercy of her guru, and she always follows her guru-rūpā-sakhī.”

Siddha pranali is a SADHANA, a long process of REALIZATION and PURIFICATION and it has to start somewhere.

It starts with receiving the information through the ears and seeing the information with my eyes on a written paper.

Since it is a sadhana, it is automatically in the stage of bhajana kriya, and it is a part of the entire complex of devotional activities that begin with diksha and archana.

Become divine to worship the divine. That is the meaning of bhuta-shuddhi in the vaidhi path of archan also.

This is why Jiva Goswami says that the highest limit of bhuta-shuddhi is contemplation of one’s siddha deha.

Of course it needs purity to finally BE that siddha deha and ACTUALLY serve with it and before the stage of ASAKTI, it is a very difficult process, but certainly the starting point is not ASAKTI.

tatra rāgānugā-mārge’nutpanna-rati-sādhaka-bhaktair api svepsita-siddha-dehaṁ manasi parikalpya bhagavat-sevādikaṁ kriyate | jāta-ratīnāṁ tu svayam eva tad-deha-sphūrtiḥ | asya tūtpannā madhura-jātīyā ratiḥ krameṇānurāga-daśāṁ prāptāsti, atas tad-deha-sphūrtiḥ sadaiva |

There, on the raganuga-path, even the sadhaka bhaktas whose rati/bhava has not yet arisen, mentally conceive of their desired siddha dehas, and thus serve the lord, etc. When rati has arisen, that body is perceived automatically. In the arisen rati of the madhura-kind, one gradually attains the stage of anuraga; then that deha will be always perceived.”
(Srila Krishna das Kaviraja Goswami´s TIKA on “Krishna Karanamritam”, verse 2)

Also we can read in the Prema Bhakti Chandrika:

yugala carana sevi, nirantara ei bhavi, anuragi thakibo sadaya |
sadhane bhavibe yaha, siddha dehe pabe taha, raga marge ei sei upaya ||
(PBC 55)

With attachment, I will always serve the feet of Sri Yugala, remaining attached to them forever. Whatever I think of during sadhana I will attain in siddha-deha; such is the means on the path of raga.

sadhane ye dhana cai, siddha-dehe taha pai, pakkapakka matra se vicara |
apakke sadhana-riti, pakile se prema-bhakti, bhakati-lakshana tattva-sara ||
(PBC 56)

The treasure I covet during my sadhana I will attain in my siddha-deha.
It is merely a matter of ripe or raw. The stage of sadhana is unripe, and the stage of prema is ripe. This is the essential truth on the characteristics of bhakti.

So, purity is the essence.

“To the degree that the ātmā becomes purified by hearing and chanting my glories, a person is able to perceive my real form and qualities and experience their sweetness, just as the eye when smeared with special ointment is able to see finer objects.”
(SB 11.14.26)

“For all new sādhakas, the contemplation of their own siddha-dehas or their meditation on Śrī Rādhā-Mādhava’s pastimes is not yet very clear; rather, they consider it to be somewhat difficult. If at first one does not have much eagerness for līlā-smaraṇa, he should perform some light or simple meditation and reflection along with hearing, chanting and so on. The sādhaka should hear and recite books that express the glory of gopī-bhāva or rāgānugā-bhajana, such as Śrīla Ṭhākura Mahāśaya’s Prārthanā and Prema-Bhakti-Candrikā, Śrīla Rūpa Gosvāmipāda’s Stavamālā, Śrīla Raghunātha Dāsa Gosvāmipāda’s Stavāvalī and Śrīla Kṛṣṇa Dāsa Siddha Bābā’s Prārthanāmṛta-Taraṅgiṇī. In this way, he endeavors to create a saṁskāra (impression) of mañjarī-bhāva internally. By doing these things, he will easily make his heart and mind suitable for performing līlā-smaraṇa.

For this reason, the author says, tat-tat-kathā-rataś cāsau: “being always engaged in hearing and chanting about Śrī Rādhā-Kṛṣṇa’s pastimes.” Because Śrī Kṛṣṇa and the stories about him are identical in nature, Śrī Kṛṣṇa himself enters the heart of the sādhaka through his ears in the form of kṛṣṇa-kathā from the mouth of a sādhu-bhakta. Then he cleanses the sādhaka’s heart and mind by driving away impurities in the form of desires and inclinations.

This has been clearly described in Śrīmad-Bhāgavatam 1.2.17:

śṛṇvatāṁ svakathāḥ kṛṣṇaḥ puṇya-śravaṇa-kīrtanaḥ |
hṛdy-antaḥ-stho hy abhadrāṇi vidhunoti suhṛt satām ||

Śrī Kṛṣṇa, who is situated in the hearts of all, is the friend of the virtuous. He drives away all inauspiciousness from those who listen to his stories, which bestow merit upon anyone who hears or recites them.”
– Srila Ananta das Babaji

Jay Sri Radhe.

Thank you, dear Prem Gopal Goswami.