The Messenger of Allah ﷺ used to say, "O Allah, You have made my form beautiful, so make my character beautiful as well."
كان رسول الله ﷺ يقول: اللهم أحسنت خلقي فأحسن خلقي.
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Ahmad (24392) and Bayhaqi in Shuab (8184, 8185) both narrated it through routes from Asim bin Sulayman (who is al-Ahwal), from Abdullah bin Harith, from Ayesha, and he related it. Its isnad is sahih. Abdullah bin Harith is Abu Walid Ansari Basri.