The following is respectfully quoted from “Perfect Conduct” with commentary by Dudjom Rinpoche:
4.b.3(b.7) Revealing secrets:
The seventh is openly revealing secret teachings to unsuitable vessels, to those with incomplete and unperfected ritual, or to those with deterioration who fear the profound.
Teaching certain aspects of secret mantra to spiritually immature individuals is a root downfall. Spiritually immature individuals are those who have not completed prerequisite training; who have not been empowered; who have incomplete practice; who have not received the three higher initiations; who, although having received empowerment, have allowed words of honor to deteriorate; who are afraid of the profound party; and who, like the śravakas and pratyekas, are not mature enough to receive the secret teachings. To intentionally expose such individuals to the uncommon substances and materials of secret mantra and their secret meaning so they lose faith constitutes the seventh downfall.