"Out of the ranks of earnest students and workers of the kind I have already described, the Master has on many occasions selected His pupils. But before He definitely accepts them He takes special precautions to assure Himself that they are really the kind of people whom He can draw into intimate contact with Himself; and that is the object of the stage called Probation."
January 1, 1970
https://en.wikiquote.org/wiki/Masters_of_Wisdom_(Theosophy)