The word(s) "understand" appears 127 time(s) in 127 verse(s) in Quran in Abdullah Yusuf Ali translation.

(51) Behold! in this are Signs for those who by tokens do understand.

(52) Allah sets forth the Parable (of two men: one) a slave under the dominion of another; He has no power of any sort; and (the other) a man on whom We have bestowed goodly favours from Ourselves, and he spends thereof (freely), privately and publicly: are the two equal? (By no means;) praise be to Allah. But most of them understand not.

(53) When We substitute one revelation for another,- and Allah knows best what He reveals (in stages),- they say, "Thou art but a forger": but most of them understand not.

(54) The seven heavens and the earth, and all beings therein, declare His glory: there is not a thing but celebrates His praise; And yet ye understand not how they declare His glory! Verily He is Oft-Forbear, Most Forgiving!

(55) And We put coverings over their hearts (and minds) lest they should understand the Qur'an, and deafness into their ears: when thou dost commemorate thy Lord and Him alone in the Qur'an, they turn on their backs, fleeing (from the Truth).

(56) And who doth more wrong than one who is reminded of the Signs of his Lord, but turns away from them, forgetting the (deeds) which his hands have sent forth? Verily We have set veils over their hearts lest they should understand this, and over their ears, deafness, if thou callest them to guidance, even then will they never accept guidance.

(57) "And how canst thou have patience about things about which thy understanding is not complete?"

(58) "So they may understand what I say:

(59) Eat (for yourselves) and pasture your cattle: verily, in this are Signs for men endued with understanding.

(60) Is it not a warning to such men (to call to mind) how many generations before them We destroyed, in whose haunts they (now) move? Verily, in this are Signs for men endued with understanding.