The Prophet (ﷺ) sent Mu`adh for some of his work. He then transmitted the rest of the tradition mentioned above.

Abu Dawud said: This tradition is sounder of the two traditions.
Sunan Abi Dawud Book 43, Hadith 11
← Previous Hadith The Messenger of Allah (ﷺ) said to us: When one of you becomes angry while standing, he should sit down. If the anger leaves him, well and good; otherwise he should lie down.

Sunan Abi Dawud Book 43, Hadith 10 Next Hadith → AbuWa'il al-Qass said: We entered upon Urwah ibn Muhammad ibn as-Sa'di. A man spoke to him and made him angry. So he stood and performed ablution; he then returned and performed ablution, and said: My father told me on the authority of my grandfather Atiyyah who reported the Messenger of Allah (ﷺ) as saying: Anger comes from the devil, the devil was created of fire, and fire is extinguished only with water; so when one of you becomes angry, he should perform ablution.

Sunan Abi Dawud Book 43, Hadith 12