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

(61) We had already, beforehand, taken the covenant of Adam, but he forgot: and We found on his part no firm resolve.

(62) And We have set on the earth mountains standing firm, lest it should shake with them, and We have made therein broad highways (between mountains) for them to pass through: that they may receive Guidance.

(63) Never did We send a messenger or a prophet before thee, but, when he framed a desire, Satan threw some (vanity) into his desire: but Allah will cancel anything (vain) that Satan throws in, and Allah will confirm (and establish) His Signs: for Allah is full of Knowledge and Wisdom:

(64) Then We placed him as (a drop of) sperm in a place of rest, firmly fixed;

(65) He Who created the heavens and the earth and all that is between, in six days, and is firmly established on the Throne (of Authority): Allah Most Gracious: ask thou, then, about Him of any acquainted (with such things).

(66) Then We told Moses by inspiration: "Strike the sea with thy rod." So it divided, and each separate part became like the huge, firm mass of a mountain.

(67) Said one who had knowledge of the Book: "I will bring it to thee within the twinkling of an eye!" Then when (Solomon) saw it placed firmly before him, he said: "This is by the Grace of my Lord!- to test me whether I am grateful or ungrateful! and if any is grateful, truly his gratitude is (a gain) for his own soul; but if any is ungrateful, truly my Lord is Free of all Needs, Supreme in Honour!"

(68) Or, Who has made the earth firm to live in; made rivers in its midst; set thereon mountains immovable; and made a separating bar between the two bodies of flowing water? (can there be another) god besides Allah? Nay, most of them know not.

(69) Thou seest the mountains and thinkest them firmly fixed: but they shall pass away as the clouds pass away: (such is) the artistry of Allah, who disposes of all things in perfect order: for he is well acquainted with all that ye do.

(70) To establish a firm place for them in the land, and to show Pharaoh, Haman, and their hosts, at their hands, the very things against which they were taking precautions.