O Allah, just as You made my external form beautiful, make my character beautiful as well
Authentic hadithعن عبد الله بن مسعود رضي الله عنه قال: قال رسول الله صلى الله عليه وسلم :«اللهم كما حَسَّنْت خَلْقِي فَحَسِّنْ خُلُقِي».
‘Abdullāh ibn Mas‘ūd (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "O Allah, just as You made my external form beautiful, make my character beautiful as well."
Explanation
Man is obliged to ask Allah, the Exalted, just as He has perfected his outward appearance and beautified it, to also perfect his inner character by granting him noble manners that complete his humanity and cleanse his inner self.
Source · Narrated by Ahmad
From the Hadith Encyclopedia (hadeethenc.com).