The word(s) "reason" appears 15 time(s) in 15 verse(s) in Quran in Muhammad Habib Shakir translation.

(11) And they swear by Allah with the most energetic of their oaths that if you command them they would certainly go forth. Say: Swear not; reasonable obedience (is desired); surely Allah is aware of what you do.

(12) Or (why is not) a treasure sent down to him, or he is made to have a garden from which he should eat? And the unjust say: You do not follow any but a man deprived of reason.

(13) And what reason have I that I should not serve Him Who brought me into existence? And to Him you shall be brought back;

(14) And what reason have you that you should not believe in Allah? And the Apostle calls on you that you may believe in your Lord, and indeed He has made a covenant with you if you are believers.

(15) And what reason have you that you should not spend in Allah's way? And Allah's is the inheritance of the heavens and the earth, not alike among you are those who spent before the victory and fought (and those who did not): they are more exalted in rank than those who spent and fought afterwards; and Allah has promised good to all; and Allah is Aware of what you do.