Śatapatha Brāhmaṇa ("of a hundred paths") 6.5.1.3

6.5.1.3

atha phenaṃ janayitvānvavadadhāti | yadeva tatpheno dvitīyaṃ rūpamasṛjyata tadevaitadrūpaṃ karotyatha yāmeva tatra mṛdaṃ saṃyauti saiva mṛdyattattatīyaṃ rūpamasṛjyataitebhyo vā eṣa rūpebhyo 'gre 'sṛjyata tebhya evainametajjanayati

He then produces foam and puts it thereto: the second form which was created (in the shape of) foam, that form he thus makes it. And the clay he now mixes is that very clay which was created as the third form. It was from these forms that he (Agni) was created at the beginning, and from them he now produces him.