The Prophet ﷺ said:

allāhumma aḥsanta khalqī fa-aḥsin khuluqi

(O Allah, You have made my beautified my form, so beautify my character ˹as well˺.)

إِنَّ النَّبِيَّ ﷺ قَالَ: (اللهُمَّ أَحْسَنْتَ خَلْقِي فَأَحْسِنْ خُلُقِي)

The Messenger of Allah ﷺ used to say, "O Allah, You have beautified my physical appearance, so beautify my character ˹as well˺."

كَانَ رَسُولُ اللَّهِ ﷺ يَقُولُ «اللَّهُمَّ حَسَّنْتَ خَلْقِي فَحَسِّنْ خُلُقِي»

Umm al-Darda said: Abu al-Darda stood up in the night to pray. He was weeping and said, 'O Allah! You made my physical form good, so make my character good!' until morning. I said, 'O Abu al-Darda, your only supplication for the entire night was for good character!' He replied, 'Umm al-Darda', the Muslim perfects his character until good character enters him into Paradise; and taints his character until his bad character enter him into Hellfire.

The Muslim is forgiven while he is asleep.' I asked, 'Abu al-Darda, how can be forgiven while he is asleep?' He said, 'His brother arises in the night, performs the night prayer, and supplicates to Allah Almighty and is answered. He supplicates for his Muslim brother and his supplication is answered.'

قَامَ أَبُو الدَّرْدَاءِ لَيْلَةً يُصَلِّي فَجَعَلَ يَبْكِي وَيَقُولُ اللَّهُمَّ أَحْسَنْتَ خَلْقِي فَحَسِّنْ خُلُقِي حَتَّى أَصْبَحَ قُلْتُ يَا أَبَا الدَّرْدَاءِ مَا كَانَ دُعَاؤُكَ مُنْذُ اللَّيْلَةِ إِلاَّ فِي حُسْنِ الْخُلُقِ؟ فَقَالَ يَا أُمَّ الدَّرْدَاءِ إِنَّ الْعَبْدَ الْمُسْلِمَ يَحْسُنُ خُلُقُهُ حَتَّى يُدْخِلَهُ حُسْنُ خُلُقِهِ الْجَنَّةَ وَيَسِيءُ خُلُقُهُ حَتَّى يُدْخِلَهُ سُوءُ خُلُقِهِ النَّارَ

وَالْعَبْدُ الْمُسْلِمُ يُغْفَرُ لَهُ وَهُوَ نَائِمٌ قُلْتُ يَا أَبَا الدَّرْدَاءِ كَيْفَ يُغْفَرُ لَهُ وَهُوَ نَائِمٌ؟ قَالَ يَقُومُ أَخُوهُ مِنَ اللَّيْلِ فَيَجْتَهِدُ فَيَدْعُو اللَّهَ عَزَّ وَجَلَّ فَيَسْتَجِيبُ لَهُ وَيَدْعُو لأَخِيهِ فَيَسْتَجِيبُ لَهُ فِيهِ

[Machine] Praise be to Allah, who made me beautiful, perfected my form, and adorned me with what I have that others do not. O Allah, just as You have made my appearance beautiful, make my character beautiful as well, and do not forsake me, for You are able to do that.

"الحَمْدُ لله الذي جمَّلنى وأحسن صورَتِى وزان مِنى مَا شَاء مِن غَيرِى، اللَّهُمَّ كمَا حَسنْتَ خلقِى فحَسن خُلُقِى ولا تجْعَلَنِى فإِنَّكَ على ذلِك قدير".

From Abu Darda, he spent a night saying: 'O Allah, as you have made my physical form good, make my character good,' until morning came. He was asked: 'Was your entire supplication throughout the night only about good character?' He replied: 'Indeed, a Muslim servant may perfect his character until his good character admits him into Paradise, and he may spoil his character until his bad character leads him into the Fire. And indeed, a Muslim servant is forgiven while he is asleep.' He was asked: 'How is that?' He said: 'Another [person] rises in the last part of the night, exerts himself in prayer and supplication to Allah – the Exalted, and He answers him, and he prays for his brother, and Allah answers him in regard to his brother.'

"أَنَّهُ بَاتَ لَيْلَةً يَقُولُ: اللَّهُمَّ أَحْسَنْتَ خَلْقِي فَحَسِّنْ خُلُقِي حَتَّي أَصْبَحَ، فَقِيلَ لَهُ: مَا كَانَ دُعَاؤكُ مُنْذُ اللَّيْلَةِ إِلَّا فيِ حُسْنِ الْخُلُقِ؟ فَقَالَ: إِنَّ الْعَبْدَ الْمُسْلِمَ يُحْسِنُ خُلُقَهُ حَتِّي يُدْخِلَه حُسْنُ خُلُقِهِ الْجَنَّةَ، وَيُسِيِءُ خُلُقَهُ حَتَّي يُدْخِلَهُ خُلُقُهُ النَّارَ، وَإنَّ الْعَبْدَ الْمُسْلِمَ لَيُغْفَرُ لَهُ وَهُو نَائِمٌ، قَيِلَ: كَيْفَ ذَاكَ؟ قَالَ: يَقُومُ آخِرَةٌ مِنَ اللَّيْلِ فَيَجْتَهِدُ فَيَدْعُو الله -تَعَالَى فَيَسْتَجِيبُ لَهُ، وَيَدْعُو لأَخِيهِ فَيَسْتَجِيبُ لَهُ فِيهِ".