The word(s) "concern" appears 40 time(s) in 37 verse(s) in Quran in Muhammad Habib Shakir translation.

(21) And those who disbelieve shall not cease to be in doubt concerning it until the hour overtakes them suddenly, or there comes on them the chastisement of a destructive day.

(22) And certainly We gave the Book to Musa, so be not in doubt concerning the receiving of it, and We made it a guide for the children of Israel.

(23) Surely your Lord will judge between them on the day of resurrection concerning that wherein they differ.

(24) Assert their relationship to their fathers; this is more equitable with Allah; but if you do not know their fathers, then they are your brethren in faith and your friends; and there is no blame on you concerning that in which you made a mistake, but (concerning) that which your hearts do purposely (blame may rest on you), and Allah is Forgiving, Merciful.

(25) O Prophet! surely We have made lawful to you your wives whom you have given their dowries, and those whom your right hand possesses out of those whom Allah has given to you as prisoners of war, and the daughters of your paternal uncles and the daughters of your paternal aunts, and the daughters of your maternal uncles and the daughters of your maternal aunts who fled with you; and a believing woman if she gave herself to the Prophet, if the Prophet desired to marry her-- specially for you, not for the (rest of) believers; We know what We have ordained for them concerning their wives and those whom their right hands possess in order that no blame may attach to you; and Allah is Forgiving, Merciful.

(26) And certainly the Shaitan found true his conjecture concerning them, so they follow him, except a party of the believers.

(27) And he has no authority over them, but that We may distinguish him who believes in the hereafter from him who is in doubt concerning it; and your Lord is the Preserver of all things

(28) None dispute concerning the communications of Allah but those who disbelieve, therefore let not their going to and fro in the cities deceive you.

(29) (Of) the day when they shall come forth, nothing concerning them remains hidden to Allah. To whom belongs the kingdom this day? To Allah, the One, the Subduer (of all).

(30) Those who dispute concerning the communications of Allah without any authority that He has given them; greatly hated is it by Allah and by-those who believe. Thus does Allah set a seal over the heart of every proud, haughty one.