Verse 7.3.1.20

sa purastādāharati | mā mā hiṃsījjanitā yaḥ pṛthivyā iti prajāpatirvai pṛthivyai janitā mā mā hiṃsītprajāpatirityetadyo vā divaṃ satyadharmā vyānaḍiti yo vā divaṃ satyadharmāsṛjatetyetadyaścāpaścandrāḥ prathamo jajāneti manuṣyā vā āpaścandrā yo manuṣyānprathamo'sṛjatetyetatkasmai devāya haviṣā vidhemeti prajāpatirvai kastasmai haviṣā vidhemetyetattāmāhṛtyāntareṇa pariśrita ātmannupadadhāti sa yaḥ prācyāṃ diśi raso'tyakṣarattamasminnetaddadhātyatho prācīmevāsminnetaddiśaṃ dadhāti

Preview of English translation:

20. From the front side he brings one, with (Vajasaneyi Samhita XII, 102), “May he not injure me who is the begetter of the Earth!”—the begetter of the Earth doubtless is Prajapati (the lord of creatures and generation): thus, “May Prajapati not injure me!”—“Or he of true ordinances who hath pervaded the sky,” that is, “Or he of true ordinances who has created the sky;”—“Or he who first begat the shining waters,”—the shining waters doubtless are the men: thus, “he who first created men;”—“To the god Ka (who?) let us do homage by offering!” Ka doubtless is Prajapati, thus, “To him let us do homage by offering!” Having brought it he puts it on the body (of the altar-site) inside the enclosing-stones: he thereby puts into him (Agni) what vital sap had flowed away from him in the eastern direction, and also the eastern region itself he bestows upon him.

For a detailled translation, including proper diacritics and footnotes, go the full English translation.