The Duties of the Heart, by Rabbi Bachye, tr. by Edwin Collins, [1909], at sacred-texts.com
(From the Gate of Humility.)
The Danger of Pride
The man who does good works is more likely to be overtaken by pride in them than by any other moral mischance; and its effect on conduct is injurious in the extreme. Therefore, among the most necessary of virtues is that one which banishes pride; and this is humility.