SB 3.12.37
maitreya uvaca
rg-yajuh-samatharvakhyan
vedan purvadibhir mukhaih
sastram ijyam stuti-stomam
prayascittam vyadhat kramat
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Maitreya said: Beginning from the front face of Brahma, gradually the four Vedas — Rk, Yajur, Sama and Atharva — became manifest. Thereafter, Vedic hymns which had not been pronounced before, priestly rituals, the subject matters of the recitation, and transcendental activities were all established, one after another.