One verse

Srimad Bhagavatam 3.3.2

3.3.2

सान्दीपने: सकृत्प्रोक्तं ब्रह्माधीत्य सविस्तरम् । तस्मै प्रादाद्वरं पुत्रं मृतं पञ्चजनोदरात् ॥ २ ॥

sandipaneh sakrt proktam brahmadhitya sa-vistaram tasmai pradad varam putram mrtam panca-janodarat

sandipaneh
of Sandipani Muni
sakrt
once only
proktam
instructed
brahma
all the Vedas with their different branches of knowledge
adhitya
after studying
sa-vistaram
in all details
tasmai
unto him
pradat
rewarded
varam
a benediction
putram
his son
mrtam
who was already dead
panca-jana
the region of the departed souls
udarat
from within.

The Lord learned all the Vedas with their different branches simply by hearing them once from His teacher, Sandipani Muni, whom He rewarded by bringing back his dead son from the region of Yamaloka.