Tantra Sāra 1.015
चतुर्विशन्मूर्तयोSस्याः कथिता वर्णदेवताः। तद्भेदः पौरुषं सूक्तं वेदाः पुरुषसूक्तगाः ॥१५॥
caturviśanmūrtayōSsyāḥ kathitā varṇadēvatāḥ। tadbhēdaḥ pauruṣaṁ sūktaṁ vēdāḥ puruṣasūktagāḥ ॥15॥
[caturviśanmūrtayōSsyāḥ = the twenty four forms of the lord; kathitā = manifest from; varṇadēvatāḥ = lords reprasented by respective syllables; tadbhēdaḥ = from it manifests; pauruṣaṁ sūktaṁ = Purusha Sūkta; vēdāḥ = The Vēdas; puruṣasūktagāḥ = manifest from Purusha Sūkta;]
The twenty four forms of the lord manifest from the 24 syllables(of Gayatri). From it manifests Purusha Sūkta. Then Vēdas manifest from Purusha Sūkta.
Note:
24 forms of the lord:
From Vāsudēva comes Kēshava, Nārāyana, Mādhava, Vāsudēva, Purushottama, and Janārdhana;
From Sankarshana comes Gōvinda, Vishnu, Madhusūdhana, Sankarshana, Adhōkshaja and Upēndra;
From Pradyumna comes Trivikrama, Vāmana, Shrīdhara, Pradyumna, Narasimha and Hari;
From Aniruddha comes Hrishīkēsha, Padmanābha, Dāmōdara, Aniruddha, Achyuta and Krishna;
From Vāsudēva comes Kēshava, Nārāyana, Mādhava, Vāsudēva, Purushottama, and Janārdhana;
From Sankarshana comes Gōvinda, Vishnu, Madhusūdhana, Sankarshana, Adhōkshaja and Upēndra;
From Pradyumna comes Trivikrama, Vāmana, Shrīdhara, Pradyumna, Narasimha and Hari;
From Aniruddha comes Hrishīkēsha, Padmanābha, Dāmōdara, Aniruddha, Achyuta and Krishna;
The Purusha Sūkta has three Pādas: 1-5, 6-10, 11-16.
They manifest from the three Pādas of Gāyatri respectively.
oṁ bhūrbhuvaḥ svaḥ = Vyahritis
tatsaviturvarēṇyaṁ = Pādas 1 (1-5) of Purusha Sūkta = Rig;
bhargō dēvasya dhīmahi = Pādas 2 (6-10) of Purusha Sūkta = Yajur;
dhiyō yō naḥ pracōdayāt = Pādas 3 (11-16) of Purusha Sūkta = Sama;
They manifest from the three Pādas of Gāyatri respectively.
oṁ bhūrbhuvaḥ svaḥ = Vyahritis
tatsaviturvarēṇyaṁ = Pādas 1 (1-5) of Purusha Sūkta = Rig;
bhargō dēvasya dhīmahi = Pādas 2 (6-10) of Purusha Sūkta = Yajur;
dhiyō yō naḥ pracōdayāt = Pādas 3 (11-16) of Purusha Sūkta = Sama;
A pictorial representation:
