The word(s) "four" appears 18 time(s) in 17 verse(s) in Quran in Muhammad Pickthal translation.

(11) As for those who accuse their wives but have no witnesses except themselves; let the testimony of one of them be four testimonies, (swearing) by Allah that he is of those who speak the truth;

(12) And it shall avert the punishment from her if she bear witness before Allah four times that the thing he saith is indeed false,

(13) Why did they not produce four witnesses? Since they produce not witnesses, they verily are liars in the sight of Allah.

(14) Allah hath created every animal of water. Of them is (a kind) that goeth upon its belly and (a kind) that goeth upon two legs and (a kind) that goeth upon four. Allah createth what He will. Lo! Allah is Able to do all things.

(15) Praise be to Allah, the Creator of the heavens and the earth, Who appointeth the angels messengers having wings two, three and four. He multiplieth in creation what He will. Lo! Allah is Able to do all things.

(16) He placed therein firm hills rising above it, and blessed it and measured therein its sustenance in four Days, alike for (all) who ask;

(17) Hast thou not seen that Allah knoweth all that is in the heavens and all that is in the earth? There is no secret conference of three but He is their fourth, nor of five but He is their sixth, nor of less than that or more but He is with them wheresoever they may be; and afterward, on the Day of Resurrection, He will inform them of what they did. Lo! Allah is Knower of all things.