explanation of the qualities of a disciple
"A worthy recipient is someone who respects their master with great faith, takes delight in Dharma practice with great diligence, has sharp mental faculties with great intelligence, and is able to keep the secrecy of the samayas. The teachings should be given to a person whose temper is steady, like the flow of a river, whose character is precise like spiritual practice, whose intentions are excellent like gold, whose mind is stable like a mountain, and who is able to surrender their body and possessions to the Dharma and one's master."
Padmasambhava, precious master of Uddiyana, has taught in detail on the necessity of having faith, diligence, and discriminating knowledge, and how one is not a suitable recipient for this Secret Mantra when lacking faith. (notes #211 & 212, LW1, pg. 257. (JOKYAB) (RY).