The word(s) "strengthen" appears 19 time(s) in 19 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) We gave Moses the Book and followed him up with a succession of messengers; We gave Jesus the son of Mary Clear (Signs) and strengthened him with the holy spirit. Is it that whenever there comes to you a messenger with what ye yourselves desire not, ye are puffed up with pride?- Some ye called impostors, and others ye slay!

(2) Those messengers We endowed with gifts, some above others: To one of them Allah spoke; others He raised to degrees (of honour); to Jesus the son of Mary We gave clear (Signs), and strengthened him with the holy spirit. If Allah had so willed, succeeding generations would not have fought among each other, after clear (Signs) had come to them, but they (chose) to wrangle, some believing and others rejecting. If Allah had so willed, they would not have fought each other; but Allah Fulfilleth His plan.

(3) And the likeness of those who spend their substance, seeking to please Allah and to strengthen their souls, is as a garden, high and fertile: heavy rain falls on it but makes it yield a double increase of harvest, and if it receives not Heavy rain, light moisture sufficeth it. Allah seeth well whatever ye do.

(4) O ye who believe! Persevere in patience and constancy; vie in such perseverance; strengthen each other; and fear Allah; that ye may prosper.

(5) If We had ordered them to sacrifice their lives or to leave their homes, very few of them would have done it: But if they had done what they were (actually) told, it would have been best for them, and would have gone farthest to strengthen their (faith);

(6) Then will Allah say: "O Jesus the son of Mary! Recount My favour to thee and to thy mother. Behold! I strengthened thee with the holy spirit, so that thou didst speak to the people in childhood and in maturity. Behold! I taught thee the Book and Wisdom, the Law and the Gospel and behold! thou makest out of clay, as it were, the figure of a bird, by My leave, and thou breathest into it and it becometh a bird by My leave, and thou healest those born blind, and the lepers, by My leave. And behold! thou bringest forth the dead by My leave. And behold! I did restrain the Children of Israel from (violence to) thee when thou didst show them the clear Signs, and the unbelievers among them said: 'This is nothing but evident magic.'

(7) For, Believers are those who, when Allah is mentioned, feel a tremor in their hearts, and when they hear His signs rehearsed, find their faith strengthened, and put (all) their trust in their Lord;

(8) Remember He covered you with a sort of drowsiness, to give you calm as from Himself, and he caused rain to descend on you from heaven, to clean you therewith, to remove from you the stain of Satan, to strengthen your hearts, and to plant your feet firmly therewith.

(9) Call to mind when ye were a small (band), despised through the land, and afraid that men might despoil and kidnap you; But He provided a safe asylum for you, strengthened you with His aid, and gave you Good things for sustenance: that ye might be grateful.

(10) Should they intend to deceive thee,- verily Allah sufficeth thee: He it is That hath strengthened thee with His aid and with (the company of) the Believers;