Appamaññāvibhaṅgasuttantabhājanīya

Abhidhammapiṭaka · Vibhaṅga · Vol. 35 · Section 742

[742] And how does a bhikkhu dwell pervading one direction with a mind (cetasā) imbued with loving-kindness (mettā)? Just as, on seeing one person who is dear and agreeable, he would feel loving-kindness, even so he pervades all beings with loving-kindness.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.