Musnad Ahmad #435
Musnad Uthman ibn Affan
Nubaih bin Wahb narrated that the eye of `Umar bin Ubaidullah became inflamed when he was in ihram, and he wanted to apply kohl to it, but Aban bin `Uthman (رضي الله عنه) forbade him to do that and told him to apply aloes to it. He said that `Uthman (رضي الله عنه) narrated from the Messenger of Allah (ﷺ) that he had done that.
About Musnad Ahmad
This hadith is #435 from Musnad Ahmad, in the Book of Musnad Uthman ibn Affan. Musnad Ahmad contains 1,374 hadiths across 8 books.