The word(s) "beware" appears 8 time(s) in 8 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) O Messenger! let not those grieve thee, who race each other into unbelief: (whether it be) among those who say "We believe" with their lips but whose hearts have no faith; or it be among the Jews,- men who will listen to any lie,- will listen even to others who have never so much as come to thee. They change the words from their (right) times and places: they say, "If ye are given this, take it, but if not, beware!" If any one's trial is intended by Allah, thou hast no authority in the least for him against Allah. For such - it is not Allah's will to purify their hearts. For them there is disgrace in this world, and in the Hereafter a heavy punishment.

(2) And this (He commands): Judge thou between them by what Allah hath revealed, and follow not their vain desires, but beware of them lest they beguile thee from any of that (teaching) which Allah hath sent down to thee. And if they turn away, be assured that for some of their crime it is Allah's purpose to punish them. And truly most men are rebellious.

(3) Obey Allah, and obey the Messenger, and beware (of evil): if ye do turn back, know ye that it is Our Messenger's duty to proclaim (the message) in the clearest manner.

(4) Deem not the summons of the Messenger among yourselves like the summons of one of you to another: Allah doth know those of you who slip away under shelter of some excuse: then let those beware who withstand the Messenger's order, lest some trial befall them, or a grievous penalty be inflicted on them.

(5) When thou lookest at them, their exteriors please thee; and when they speak, thou listenest to their words. They are as (worthless as hollow) pieces of timber propped up, (unable to stand on their own). They think that every cry is against them. They are the enemies; so beware of them. The curse of Allah be on them! How are they deluded (away from the Truth)!

(6) O ye who believe! Truly, among your wives and your children are (some that are) enemies to yourselves: so beware of them! But if ye forgive and overlook, and cover up (their faults), verily Allah is Oft-Forgiving, Most Merciful.

(7) Let him beware! If he desist not, We will drag him by the forelock,-

(8) Nay, were ye to know with certainty of mind, (ye would beware!)