The word(s) "weak" appears 18 time(s) in 16 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) O ye who believe! When ye deal with each other, in transactions involving future obligations in a fixed period of time, reduce them to writing Let a scribe write down faithfully as between the parties: let not the scribe refuse to write: as Allah Has taught him, so let him write. Let him who incurs the liability dictate, but let him fear His Lord Allah, and not diminish aught of what he owes. If they party liable is mentally deficient, or weak, or unable Himself to dictate, Let his guardian dictate faithfully, and get two witnesses, out of your own men, and if there are not two men, then a man and two women, such as ye choose, for witnesses, so that if one of them errs, the other can remind her. The witnesses should not refuse when they are called on (For evidence). Disdain not to reduce to writing (your contract) for a future period, whether it be small or big: it is juster in the sight of Allah, More suitable as evidence, and more convenient to prevent doubts among yourselves but if it be a transaction which ye carry out on the spot among yourselves, there is no blame on you if ye reduce it not to writing. But take witness whenever ye make a commercial contract; and let neither scribe nor witness suffer harm. If ye do (such harm), it would be wickedness in you. And fear Allah. And Allah teaches you. And Allah is well acquainted with all things.

(2) How many of the prophets fought (in Allah's way), and with them (fought) Large bands of godly men? but they never lost heart if they met with disaster in Allah's way, nor did they weaken (in will) nor give in. And Allah Loves those who are firm and steadfast.

(3) To those weak of understanding Make not over your property, which Allah hath made a means of support for you, but feed and clothe them therewith, and speak to them words of kindness and justice.

(4) Allah doth wish to lighten your (difficulties): For man was created weak (in flesh).

(5) And why should ye not fight in the cause of Allah and of those who, being weak, are ill-treated (and oppressed)?- Men, women, and children, whose cry is: "Our Lord! Rescue us from this town, whose people are oppressors; and raise for us from thee one who will protect; and raise for us from thee one who will help!"

(6) When angels take the souls of those who die in sin against their souls, they say: "In what (plight) Were ye?" They reply: "weak and oppressed Were we in the earth." They say: "Was not the earth of Allah spacious enough for you to move yourselves away (From evil)?" Such men will find their abode in Hell,- What an evil refuge! -

(7) Except those who are (really) weak and oppressed - men, women, and children - who have no means in their power, nor (a guide-post) to their way.

(8) They ask thy instruction concerning the women say: Allah doth instruct you about them: And (remember) what hath been rehearsed unto you in the Book, concerning the orphans of women to whom ye give not the portions prescribed, and yet whom ye desire to marry, as also concerning the children who are weak and oppressed: that ye stand firm for justice to orphans. There is not a good deed which ye do, but Allah is well-acquainted therewith.

(9) And We made a people, considered weak (and of no account), inheritors of lands in both east and west, - lands whereon We sent down Our blessings. The fair promise of thy Lord was fulfilled for the Children of Israel, because they had patience and constancy, and We levelled to the ground the great works and fine buildings which Pharaoh and his people erected (with such pride).

(10) For the present, Allah hath lightened your (task), for He knoweth that there is a weak spot in you: But (even so), if there are a hundred of you, patient and persevering, they will vanquish two hundred, and if a thousand, they will vanquish two thousand, with the leave of Allah: for Allah is with those who patiently persevere.