The word(s) "firm" appears 109 time(s) in 108 verse(s) in Quran in Abdullah Yusuf Ali translation.

(71) But there came to be a void in the heart of the mother of Moses: She was going almost to disclose his (case), had We not strengthened her heart (with faith), so that she might remain a (firm) believer.

(72) When he reached full age, and was firmly established (in life), We bestowed on him wisdom and knowledge: for thus do We reward those who do good.

(73) "And my brother Aaron - He is more eloquent in speech than I: so send him with me as a helper, to confirm (and strengthen) me: for I fear that they may accuse me of falsehood."

(74) So patiently persevere: for verily the promise of Allah is true: nor let those shake thy firmness, who have (themselves) no certainty of faith.

(75) He created the heavens without any pillars that ye can see; He set on the earth mountains standing firm, lest it should shake with you; and He scattered through it beasts of all kinds. We send down rain from the sky, and produce on the earth every kind of noble creature, in pairs.

(76) "O my son! establish regular prayer, enjoin what is just, and forbid what is wrong: and bear with patient constancy whatever betide thee; for this is firmness (of purpose) in (the conduct of) affairs.

(77) It is Allah Who has created the heavens and the earth, and all between them, in six Days, and is firmly established on the Throne (of Authority): ye have none, besides Him, to protect or intercede (for you): will ye not then receive admonition?

(78) That which We have revealed to thee of the Book is the Truth,- confirming what was (revealed) before it: for Allah is assuredly- with respect to His Servants - well acquainted and Fully Observant.

(79) Nay! he has come with the (very) Truth, and he confirms (the Message of) the messengers (before him).

(80) And he who brings the Truth and he who confirms (and supports) it - such are the men who do right.