The word(s) "weak" appears 45 time(s) in 41 verse(s) in Quran in Mohsin Khan translation.

(21) They said: "By Allah! You will never cease remembering Yusuf (Joseph) until you become weak with old age, or until you be of the dead."

(22) And when the caravan departed, their father said: "I do indeed feel the smell of Yusuf (Joseph), if only you think me not a dotard (a person who has weakness of mind because of old age)."

(23) And they all shall appear before Allah (on the Day of Resurrection); then the weak will say to those who were arrogant (chiefs): "Verily, we were following you; can you avail us anything against Allah's Torment?" They will say: "Had Allah guided us, we would have guided you. It makes no difference to us (now) whether we rage, or bear (these torments) with patience; there is no place of refuge for us."

(24) And when Our Clear Verses are recited to them, those who disbelieve (the rich and strong among the pagans of Quraish who live a life of luxury) say to those who believe (the weak, poor companions of Prophet Muhammad صلى الله عليه وسلم who have a hard life): "Which of the two groups (i.e. believers or disbelievers) is best in (point of) position and as regards station (place of council for consultation)."

(25) Say (O Muhammad صلى الله عليه وسلم) whoever is in error, the Most Gracious (Allah) will extend (the rope) to him, until, when they see that which they were promised, either the torment or the Hour, they will come to know who is worst in position, and who is weaker in forces. [This is the answer to the question in Verse No.19:73]

(26) "Go you and your brother with My Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.), and do not, you both, slacken and become weak in My Remembrance.

(27) O mankind! A similitude has been coined, so listen to it (carefully): Verily those on whom you call besides Allah, cannot create (even) a fly, even though they combine together for the purpose. And if the fly snatches away a thing from them, they will have no power to release it from the fly. So weak are (both) the seeker and the sought.

(28) Verily, Fir'aun (Pharaoh) exalted himself in the land and made its people sects, weakening (oppressing) a group (i.e. Children of Israel) among them: killing their sons, and letting their females live. Verily, he was of the Mufsidun (i.e. those who commit great sins and crimes, oppressors, tyrants).

(29) And We wished to do a favour to those who were weak (and oppressed) in the land, and to make them rulers and to make them the inheritors,

(30) The likeness of those who take (false deities as) Auliya' (protectors, helpers) other than Allah is the likeness of a spider who builds (for itself) a house; but verily, the frailest (weakest) of houses is the spider's house - if they but knew.