The word(s) "concerning" appears 38 time(s) in 35 verse(s) in Quran in Muhammad Habib Shakir translation.

(31) Those who do not believe in it would hasten it on, and those who believe are in fear from it, and they know that it is the truth. Now most surely those who dispute obstinately concerning the hour are in a great error.

(32) And We gave them clear arguments in the affair, but they did not differ until after knowledge had come to them out of envy among themselves; surely your -Lord will judge between them on the day of resurrection concerning that wherein they differed.

(33) Nay! they say: He has forged it. Say: If I have forged it, you do not control anything for me from Allah; He knows best what you utter concerning it; He is enough as a witness between me and you, and He is the Forgiving, the Merciful.

(34) And those who disbelieve say concerning those who believe: If it had been a good, they would not have gone ahead of us therein. And as they do not seek to be rightly directed thereby, they say: It is an old lie.

(35) Have you not seen those who have become hypocrites? They say to those of their brethren who disbelieve from among the followers of the Book: If you are driven forth, we shall certainly go forth with you, and we will never obey any one concerning you, and if you are fought against, we will certainly help you, and Allah bears witness that they are most surely liars.