Allah accepts Repentance and responds to Supplications
Here Allah reminds His servants that He accepts repentance. If they turn to Him and come back to Him, then by His kindness and generosity He forgives, overlooks and conceals (their sins), as He says;
وَمَن يَعْمَلْ سُوءاً أَوْ يَظْلِمْ نَفْسَهُ ثُمَّ يَسْتَغْفِرِ اللَّهَ يَجِدِ اللَّهَ غَفُوراً رَّحِيماً
And whoever does evil or wrongs himself but afterwards seeks Allah's forgiveness, he will find Allah Oft-Forgiving, Most Merciful. (4;110)
It was reported in Sahih Muslim that Anas bin Malik, may Allah be pleased with him, said,
"The Messenger of Allah said;
اللهُ تَعَالَى أَشَدُّ فَرَحًا بِتَوْبَةِ عَبْدِهِ حِينَ يَتُوبُ إِلَيْهِ مِنْ أَحَدِكُمْ كَانَتْ رَاحِلَتُهُ بِأَرْضِ فَلَةٍ فَانْفَلَتَتْ مِنْهُ وَعَلَيْهَا طَعَامُهُ وَشَرَابُهُ فَأَيِسَ مِنْهَا فَأَتَى شَجَرَةً فَاضْطَجَعَ فِي ظِلِّهَا قَدْ أَيِسَ مِنْ رَاحِلَتِهِ فَبَيْنَمَا هُوَ كَذَلِكَ إِذَا هُوَ بِهَا قَايِمَةً عِنْدَهُ فَأَخَذَ بِخِطَامِهَا ثُمَّ قَالَ مِنْ شِدَّةِ الْفَرَحِ اللْهُمَّ أَنْتَ عَبْدِي وَأَنَا رَبُّكَ أَخْطَأَ مِنْ شِدَّةِ الْفَرَح
Allah is more pleased with the repentance of His servant than anyone of you who loses his riding beast in a barren land, and it was carrying his food and drink; he despairs of ever finding it, so he comes to a tree and lies down in its shade, having given up all hope of finding his riding beast; then whilst he is there like that, suddenly he sees it standing near him, so he takes hold of its reins and because of his great joy he says,
"O Allah, You are my slave and I am Your Lord!" -- i.e., he makes a mistake because of his great joy."
A similar report was also narrated in the Sahih from Abdullah bin Mas`ud, may Allah be pleased with him.
Allah says,
وَهُوَ الَّذِي يَقْبَلُ التَّوْبَةَ عَنْ عِبَادِهِ
And He it is Who accepts repentance from His servants,
It was reported that Az-Zuhri said, concerning this Ayah, that Abu Hurayrah, may Allah be pleased with him, said,
"The Messenger of Allah said;
اللهُ أَشَدُّ فَرَحًا بِتَوْبَةِ عَبْدِهِ مِنْ أَحَدِكُمْ يَجِدُ ضَالَّتَهُ فِي الْمَكَانِ الَّذِي يَخَافُ أَنْ يَقْتُلَهُ فِيهِ الْعَطَش
Allah rejoices more over the repentance of His servant than one of you feels when he finds his lost camel in a place where he had feared that he would die of thirst."
Hammam bin Al-Harith said,
"Ibn Mas`ud was asked about a man who commits immoral sins with a woman and then marries her.
He said, `There is nothing wrong with that,' and recited;
وَهُوَ الَّذِي يَقْبَلُ التَّوْبَةَ عَنْ عِبَادِهِ
And He it is Who accepts repentance from His servants."
وَيَعْفُو عَنِ السَّيِّيَاتِ
and forgives sins,
means, He will accept repentance in the future, and He forgives past sins.
وَيَعْلَمُ مَا تَفْعَلُونَ
and He knows what you do.
means, He knows all your deeds and actions and words, yet He still accepts the repentance of those who repent to Him