The word(s) "firmness" appears 6 time(s) in 6 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) Those who show patience, firmness and self-control; who are true (in word and deed); who worship devoutly; who spend (in the way of Allah); and who pray for forgiveness in the early hours of the morning.

(2) And We ordained laws for him in the tablets in all matters, both commanding and explaining all things, (and said): "Take and hold these with firmness, and enjoin thy people to hold fast by the best in the precepts: soon shall I show you the homes of the wicked,- (How they lie desolate)."

(3) Remember thy Lord inspired the angels (with the message): "I am with you: give firmness to the Believers: I will instil terror into the hearts of the Unbelievers: smite ye above their necks and smite all their finger-tips off them."

(4) O ye who believe! fight the unbelievers who gird you about, and let them find firmness in you: and know that Allah is with those who fear Him.

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

(6) "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.