"And do thou (O reader!) Bring thy Lord to remembrance in thy (very) soul, with humility and in reverence, without loudness in words, in the mornings and evenings; and be not thou of those who are unheedful."
 

(Holy Qur'an (Yusufali) 7:205)

"Call on your Lord with humility and in private: for God loveth not those who trespass beyond bounds."
 

(Holy Qur'an (Yusufali) 7:55)

"They fall down on their faces in tears, and it increases their (earnest) humility."
 

(Holy Qur'an (Yusufali) 17:109)

"Hazrath's garment was very old and patched. When somebody drew the attention of him towards it he replied, "such dress, when worn by men of status and position, make them submissive to God and kind-hearted towards man, and faithful Muslims can conveniently follow the example. Vicious pleasures of this world and salvation are like two enemies or two roads running in opposite directions, or towards opposite poles, one to the North and the other to the South. Whoever likes to gain the pleasures and pomps of this world will hate austerity in life, which is necessary to gain salvation. Vice versa will be the attitude of a man desirous of achieving Eternal Bliss. One has to adopt one of the two ways of life, as they both cannot be brought together, a man has to choose one of the either."
 

(Nahjul Balagha: Sermons, letters and saying of Hazrat Ali (Second American edition, 1981), Sayings of Hazrat Ali 103, p. 283)