What is the difference between tawbah (turning to Allaah in repentance) and istaghfaar (seeking forgiveness)? When do we use them?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ʻalayhi wa sallam, is His slave and Messenger. 

The scholars made a distinction between istighfaar (seeking forgiveness from Allaah) and tawbah (repentance); we shall quote some of their statements on this topic.

The author of Faydh Al-Baari said, “You should know that Shaykh Shams Ad-Deen Al-Jazari underlined the distinction between istighfaar and tawbah stating that tawbah is sought for oneself only but that one can make istighfaar for himself or others. Also, tawbah indicates remorse for past sins and resolve to give them up in the future, whereas istighfaar means seeking forgiveness for past sins and is not necessarily accompanied by the resolve to give them up in the future.”

Tawbah is not valid unless the due conditions of its validity are met, namely quitting the sin, resolving never to commit it again, feeling regret for having committed it, and the settlement of liabilities, if any (i.e. if the sin involved taking people's rights unlawfully, then the sinner has to give them back their rights). As for istighfaar, it is to ask Allaah for His pardon. It may be accompanied by sincere repentance and it may not. In this case, it does not necessitate forgiveness; it is like the supplication, which may be answered and may not be answered, as Allaah wishes.

Shaykhul-Islam Ibn Taymiyyah said:

“Istighfaar means asking forgiveness from Allaah, which falls under the category of supplication and invocation. It often accompanies repentance, and it is enjoined (to ask for forgiveness with repentance); the sinner may turn to Allaah in repentance but not supplicate for forgiveness, and he may do the opposite ... Repentance cancels out past sins; however, seeking forgiveness without repentance does not necessitate forgiveness. Rather, it is a means to obtain forgiveness.”

Ibn Rajab, may Allaah have mercy upon you, wrote:

“If one said, 'Astaghfirullaah' (I seek forgiveness of Allaah) while he does not harbor the intention of giving up the sin in his heart, he is supplicating for forgiveness, as if he is saying, 'O Lord, forgive me.' This is commendable, and his supplication shall hopefully be answered. Those who referred to istighfaar as 'the repentance of the liars' mean that it is not equivalent to repentance, as some people may assume. This is true in the sense that repentance cannot be attained while the sinner is persistent on committing the sin. When the person says, 'O Allaah! Forgive me,' this is supplicating for forgiveness, and the same rulings pertaining to supplication apply to it; it may be accepted by Allaah, Who would forgive the person supplicating Him, especially if the person implores Him with a humbled heart in one of the times when supplications are most likely answered, such as the last third of the night and after the obligatory prayers.”

As for the time for repentance and seeking forgiveness, repentance is obligatory upon committing any sin; it is a lifetime duty. Allaah, The Exalted, says (what means): {And whoever does not repent - then it is those who are the wrongdoers.} [Quran 49:11] Therefore, some of the righteous predecessors said, "One should turn to Allaah in repentance in mornings and evenings or otherwise he is among the wrongdoers." When istighfaar is accompanied by repentance, then that is the perfect way with which the Muslim is enjoined to turn to Allaah. If istighfaar is unaccompanied by repentance, then that is a form of supplication.

Finally, there are many occasions when it is an act of Sunnah to seek forgiveness, such as after the obligatory prayers, in the reported morning and evening thikr (remembrance of Allaah), at the end of gatherings, after performing ablution, in the last third of the night, and at other blessed times.

Allaah knows best.