The Holy Prophet (S) said: "The honour of a believer lies in his vigilance at night and his esteem lies in his autonomy from people."
Bihar-ul-Anwar, vol. 77, p. 20
Imam Amir ul Mu'mineen ‘Ali (‘a) said: "He who sleeps too much at night, will lose something of his deeds (i.e., night prayers) which he cannot gain during the day-time."
Imam as-Sadiq (‘a) said that Allah (s.w.t.) in a revelation told Moses, the son of 'Imran (‘a): "O' you son of 'Imran! Those who only claim that they love Me, tell a lie, for when the night falls they neglect Me."
Bihar-ul-Anwar, vol. 13, p. 329
Imam as-Sadiq (‘a) said: "Never miss midnight prayers, because, in fact, the real loser is he who misses (the advantage of) the midnight prayer."
Bihar-ul-Anwar, vol. 83, p. 127
Imam as-Sadiq (‘a) said: "The Messenger of Allah (S) told Gabriel to preach to him, and he said: 'Live howsoever you like but you will surely die; love whatsoever you like but you will surely depart from it; do whatsoever you like but you will certainly meet it (and receive its reward). The honour of a (Muslim) believer is his midnight prayers, and his nobility is his refraining from (ruining) people's reputation"
Khisal by Saduq, p. 7
Imam as-Sadiq (‘a) said: "There are three things which are the honour of a believer and his ornament both in this world and the next. They are: prayers in the last part of night (night prayers), not coveting what people possess in their hands, and the love (and leadership) of an Imam from the progeny of Muhammad (S)."
Bihar-ul-Anwar, vol. 75, p. 107
Imam Muhammad-ibn-’Ali, Jawad-ul-'A'immah, (‘a) said: "He who has confidence in Allah, sees joy; and he who trusts on Him, He will suffice his affairs."
Bihar-ul-Anwar, vol. 78, p. 79