The word(s) "middle" appears 3 time(s) in 3 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) Guard strictly your (habit of) prayers, especially the middle Prayer; and stand before Allah in a devout (frame of mind).

(2) Say: "Call upon Allah, or call upon Rahman: by whatever name ye call upon Him, (it is well): for to Him belong the Most Beautiful Names. Neither speak thy Prayer aloud, nor speak it in a low tone, but seek a middle course between."

(3) Then We have given the Book for inheritance to such of Our Servants as We have chosen: but there are among them some who wrong their own souls; some who follow a middle course; and some who are, by Allah's leave, foremost in good deeds; that is the highest Grace.