Srila Prabhupada regarding The power of hearing from the pure devotee

‘sādhu-saṅga’, ‘sādhu-saṅga’–sarva-śāstre kaya
lava-mātra sādhu-saṅge sarva-siddhi haya
SYNONYMS
sādhusaṅga sādhusaṅga—association with pure devotees; sarvaśāstre—all the revealed scriptures; kaya—say; lavamātra—even for a moment; sādhusaṅge—by association with a devotee; sarvasiddhi—all success; haya—there is.
TRANSLATION
 
“The verdict of all revealed scriptures is that by even a moment’s association with a pure devotee, one can attain all success.

PURPORT
According to astronomical calculations, lava is one eleventh of one second
Chaitanya charitamrta Madhya-lila 22.54