Guru puja to Srila Prabhupada

If a person is a brahmana, then his natural qualification will be like this. What is that? Satyam: he is truthful. In any circumstances he will be truthful. Even to an enemy he will disclose the secret, "This is the fact." That is truthfulness, not that I am very truthful, but when my interest is jeopardized, I tell lie. That is not truthfulness. Truthfulness means at any circumstances one will speak the plain truth. That is truthfulness
(Lecture – July 9, 1968, Montreal)

(So all devotees who take second initiation, brahmana initiation, means we take the responsibility to always speak the truth, otherwise we are not brahmanas)

Truths and Lies