From the point of view of individual development and for those who are still at the beginning of the path, to know how to remain silent before what one does not understand is one of the things which would help most in the progress—to know how to remain silent, not only externally, without uttering a word, but also to know how to be silent within, so that the mind does not assert its ignorance with its usual presumptuousness, does not try to understand with an instrument that is incapable of understanding, that it may know its own weakness and open simply, quietly, waiting until the time has come for it to receive the light, because only the Light, the true Light, can give it understanding. It is not all that it has learnt nor all that it has observed nor all its so-called experience of life, it is something else which is completely beyond it. And until this something else—which is the expression of the Grace—manifests within it, if, very quietly, very modestly the mind remains silent and does not try to understand and, above all, to judge, things would go much faster.
Ref : Questions and Answers 1957-1958