Humility is one of the twelve attributes of the Mother’s symbol.
To be humble means for the mind, the vital and the body never to forget that without the Divine they know nothing, are nothing and can do nothing; without the Divine they are nothing but ignorance, chaos and impotence. The Divine alone is Truth, Life, Power, Love, Felicity.
Therefore the mind, the vital, and the body must learn and feel, once and for all, that they are wholly incapable of understanding and judging the Divine, not only in his essence but also in his action and manifestation.
This is the only true humility and with it come quiet and peace.
This is also the surest shield against all hostile attack. Indeed, in the human being it is always the door of pride at which the Adversary knocks, for it is this door which opens to let him enter.
The Mother – Words of the Mother: CWM, Vol. 14, pp 152-53
…. Humility is that state of consciousness in which, whatever the realisation, you know the infinite is still in front of you….
The Mother – Questions and Answers: CWM, Vol. 3, p175
Perhaps one could say that it [spiritual humility] is to be aware of the relativity of what has been done compared with what is still to be done—and also to be conscious of one’s being nothing without the Divine Grace.
Sri Aurobindo – Letter On Yoga: CWSA, Vol. 28, p432
All was abolished save her naked self
And the prostrate yearning of her surrendered heart:
There was no strength in her, no pride of force;
The lofty burning of desire had sunk
Ashamed, a vanity of separate self,
The hope of spiritual greatness fled,
Salvation she asked not nor a heavenly crown:
Humility seemed now too proud a state.
Sri Aurobindo – Savitri : CWSA, Vol. 34, Book Seven, p522