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

(1) Those who forswear their wives must wait four months; then, if they change their mind, lo! Allah is Forgiving, Merciful.

(2) Such of you as die and leave behind them wives, they (the wives) shall wait, keeping themselves apart, four months and ten days. And when they reach the term (prescribed for them) then there is no sin for you in aught that they may do with themselves in decency. Allah is informed of what ye do.

(3) And when Abraham said (unto his Lord): My Lord! Show me how Thou givest life to the dead, He said: Dost thou not believe? Abraham said: Yea, but (I ask) in order that my heart may be at ease. (His Lord) said: Take four of the birds and cause them to incline unto thee, then place a part of them on each hill, then call them, they will come to thee in haste, and know that Allah is Mighty, Wise.

(4) And if ye fear that ye will not deal fairly by the orphans, marry of the women, who seem good to you, two or three or four; and if ye fear that ye cannot do justice (to so many) then one (only) or (the captives) that your right hands possess. Thus it is more likely that ye will not do injustice.

(5) And unto you belongeth a half of that which your wives leave, if they have no child; but if they have a child then unto you the fourth of that which they leave, after any legacy they may have bequeathed, or debt (they may have contracted, hath been paid). And unto them belongeth the fourth of that which ye leave if ye have no child, but if ye have a child then the eighth of that which ye leave, after any legacy ye may have bequeathed, or debt (ye may have contracted, hath been paid). And if a man or a woman have a distant heir (having left neither parent nor child), and he (or she) have a brother or a sister (only on the mother's side) then to each of them twain (the brother and the sister) the sixth, and if they be more than two, then they shall be sharers in the third, after any legacy that may have been bequeathed or debt (contracted) not injuring (the heirs by willing away more than a third of the heritage) hath been paid. A commandment from Allah. Allah is Knower, Indulgent.

(6) As for those of your women who are guilty of lewdness, call to witness four of you against them. And if they testify (to the truth of the allegation) then confine them to the houses until death take them or (until) Allah appoint for them a way (through new legislation).

(7) Travel freely in the land four months, and know that ye cannot escape Allah and that Allah will confound the disbelievers (in His Guidance).

(8) Lo! the number of the months with Allah is twelve months by Allah's ordinance in the day that He created the heavens and the earth. four of them are sacred: that is the right religion. So wrong not yourselves in them. And wage war on all of the idolaters as they are waging war on all of you. And know that Allah is with those who keep their duty (unto Him).

(9) (Some) will say: They were three, their dog the fourth, and (some) say: Five, their dog the sixth, guessing at random; and (some) say: Seven, and their dog the eighth. Say (O Muhammad): My Lord is Best Aware of their number. None knoweth them save a few. So contend not concerning them except with an outward contending, and ask not any of them to pronounce concerning them.

(10) And those who accuse honourable women but bring not four witnesses, scourge them (with) eighty stripes and never (afterward) accept their testimony - They indeed are evil-doers -