What does « Repentance / Return » mean in the Quran?

And they ask you about menstruation. Say, "It is harm, so keep away from wives during menstruation. And do not approach them until they are pure. And when they have purified themselves, then come to them from where Allah has ordained for you. Indeed, Allah loves those who are constantly repentant and loves those who purify themselves."

And if you do not, then be informed of a war [against you] from Allah and His Messenger. But if you repent, you may have your principal - [thus] you do no wrong, nor are you wronged.

Except for those who repent after that and correct themselves. For indeed, Allah is Forgiving and Merciful.

Indeed, those who reject the message after their belief and then increase in disbelief - never will their [claimed] repentance be accepted, and they are the ones astray.

Not for you, [O Muhammad, but for Allah], is the decision whether He should [cut them down] or forgive them or punish them, for indeed, they are wrongdoers.

And the two who commit it among you, dishonor them both. But if they repent and correct themselves, leave them alone. Indeed, Allah is ever Accepting of repentance and Merciful.

The repentance accepted by Allah is only for those who do wrong in ignorance [or carelessness] and then repent soon after. It is those to whom Allah will turn in forgiveness, and Allah is ever Knowing and Wise.

But repentance is not [accepted] of those who [continue to] do evil deeds up until, when death comes to one of them, he says, "Indeed, I have repented now," or of those who die while they are disbelievers. For them We have prepared a painful punishment.

Allah wants to make clear to you [the lawful from the unlawful] and guide you to the [good] practices of those before you and to accept your repentance. And Allah is Knowing and Wise.

Allah wants to accept your repentance, but those who follow [their] passions want you to digress [into] a great deviation.

And We did not send any messenger except to be obeyed by permission of Allah. And if, when they wronged themselves, they had come to you, [O Muhammad], and asked forgiveness of Allah and the Messenger had asked forgiveness for them, they would have found Allah Accepting of repentance and Merciful.

And never is it for a believer to kill a believer except by mistake. And whoever kills a believer by mistake - then the freeing of a believing slave and a compensation payment presented to the deceased's family [is required] unless they give [up their right as] charity. But if the deceased was from a people at war with you and he was a believer - then [only] the freeing of a believing slave; and if he was from a people with whom you have a treaty - then a compensation payment presented to his family and the freeing of a believing slave. And whoever does not find [one or cannot afford to buy one] - then [instead], a fast for two months consecutively, [seeking] acceptance of repentance from Allah. And Allah is ever Knowing and Wise.

Except for those who repent, correct themselves, hold fast to Allah, and are sincere in their religion for Allah, for those will be with the believers. And Allah is going to give the believers a great reward.

Except for those who return [repenting] before you apprehend them. And know that Allah is Forgiving and Merciful.

But whoever repents after his wrongdoing and reforms, indeed, Allah will turn to him in forgiveness. Indeed, Allah is Forgiving and Merciful.

And they thought there would be no [resulting] punishment, so they became blind and deaf. Then Allah turned to them in forgiveness; then [again] many of them became blind and deaf. And Allah is Seeing of what they do.

So will they not repent to Allah and seek His forgiveness? And Allah is Forgiving and Merciful.

And when those come to you who believe in Our verses, say, "Peace be upon you. Your Lord has decreed upon Himself mercy: that any of you who does wrong out of ignorance and then repents after that and corrects himself - indeed, He is Forgiving and Merciful."

And when Moses arrived at Our appointed time and his Lord spoke to him, he said, "My Lord, show me [Yourself] that I may look at You." [Allah] said, "You will not see Me, but look at the mountain; if it should remain in place, then you will see Me." But when his Lord appeared to the mountain, He rendered it level, and Moses fell unconscious. And when he awoke, he said, "Exalted are You! I have repented to You, and I am the first of the believers."

But those who committed misdeeds and then repented after them and believed - indeed your Lord, thereafter, is Forgiving and Merciful.

And [it is] an announcement from Allah and His Messenger to the people on the day of the greater pilgrimage that Allah is disassociated from the disbelievers, and [so is] His Messenger. So if you repent, that is best for you; but if you turn away - then know that you will not cause failure to Allah. And give tidings to those who disbelieve of a painful punishment.

And when the sacred months have passed, then kill the polytheists wherever you find them and capture them and besiege them and sit in wait for them at every place of ambush. But if they should repent, establish prayer, and give zakah, let them [go] on their way. Indeed, Allah is Forgiving and Merciful.

But if they repent, establish prayer, and give zakah, then they are your brothers in religion; and We detail the verses for a people who know.

And remove the fury in the believers' hearts. And Allah turns in forgiveness to whom He wills; and Allah is Knowing and Wise.

Then Allah will accept repentance after that for whom He wills; and Allah is Forgiving and Merciful.