Gobhilagrihyasutra 2.10.26

2.10.26

utsṛjyā 'pām añjalim ācāryo dakṣiṇena pāṇinā dakṣiṇaṃ pāṇiṃ sāṅguṣṭhaṃ gṛhṇāti: devasya te savituḥ prasave 'śvinor bāhubhyāṃ, pūṣṇo hastābhyāṃ hastaṃ gṛhṇāmy asāv iti.

Having let the water run out of his joined hands (over the student's hands), the teacher with his right hand seizes (the student's) right hand together with the thumb, with (the formula), 'By the impulse of the god Savitri, with the arms of the two Asvins, with Pûshan's hands I seize thy hand, N.N.!' (ibid. 18).