The Duties of the Heart, by Rabbi Bachye, tr. by Edwin Collins, [1909]
He who has true humility will be free from all pride, conceit, self-praise and self-glorification, even in his secret thoughts, when he is occupied in works of charity or other virtuous or righteous acts, whether commanded or not; and in his own soul he will account them as nothing in comparison to the greatness of his obligation to God.