In The Name of Allaah, The Most Merciful, The Bestower of Mercy
Shaikh Muhammad Baazmool (may Allaah preserve him) stated in [بُغْيَةُ المُتَطَوِّع فِى صَلاَةِ التَّطوُّع . page 120:
It is incumbent upon a servant (of Allaah) that he is eager to fear Allaah (The Most High); pays close attention and be very attentive to (Allaah’s commands and prohibitions) and not to fall into disobedience. And if he commits sin, he should proceed-without delay- towards repentance, and turns repentantly to Allaah with complete submission. And indeed the Messenger (sallal-laahu-alayhi-wasallam) legislated this Salaah [for a person when he performs the act of] repentance.
Asmaa’a Ibn Al-Hakam Al-Fizaariy said: “I heard Ali saying, ‘Indeed I was a man who, when I heard a Hadeeth from the Messenger of Allaah (sallal-laahu-alayhi-wasallam), Allaah benefited me from it as much as He wished to benefit me through it; and if I heard it (i.e. a hadeeth) from one of his (i.e. the Messenger’s) companions, I would ask him to swear (that it was true), so if he swore, I would believe him. And indeed AbuBakr narrated to me – and AbuBakr spoke the truth- that he heard the Messenger of Allaah (sallal-laahu-alayhi-wasallam) say, “There is no servant (of Allaah) who commits a sin, then performs Wudhu perfectly, and stand and prays two Rak’ahs, and then seeks forgiveness from Allaah, except that Allaah forgives him.” Then he recited this Ayah:
وَالَّذِينَ إِذَا فَعَلُواْ فَاحِشَةً أَوْ ظَلَمُواْ أَنْفُسَهُمْ ذَكَرُواْ اللّهَ فَاسْتَغْفَرُواْ لِذُنُوبِهِمْ وَمَن يَغْفِرُ الذُّنُوبَ إِلاَّ اللّهُ وَلَمْ يُصِرُّواْ عَلَى مَا فَعَلُواْ وَهُمْ يَعْلَمُونَ
”And those who, when they have committed Fahishah (illegal sexual intercourse etc.) or wronged themselves with evil, remember Allah and ask forgiveness for their sins; – and none can forgive sins but Allah – And do not persist in what (wrong) they have done, while they know”. [3:135] [Ref A]
[Ref A: Hadeeth Reported by Imaam Tirmidhee (rahimahullaah)- Number 406; Imaam Abu Dawud (rahimahullaah) -Number 1521 & others. And Imaam Albaani (rahimahullaah) declared it ‘Hasan’ in Saheeh Sunan At-Tirmidhee. Number 1/128]