Varahashrautasutra 2.2.2.4

2.2.2.4

tvaṃ no agne - sa tvaṃ no agne - taṃ tvā śociṣṭha dīdivaḥ - adhā hyagne - evā hyagna iti dvipadā uttarataḥ

With ‘You to us, O Agni’, ‘So you to us, O Agni’, ‘Thee, most radiant, shining one’, ‘For thus, O Agni’, ‘Truly thus, O Agni’, [he places] two-footed [verses/bricks] on the north.