"Uthman bin Abi Al-As" and he narrated something similar in Mursal form.
Sunan an-Nasa'i Book 22, Hadith 323
← Previous Hadith "I heard the Messenger of Allah say: 'It is a good fast to fast three days of each month".

Sunan an-Nasa'i Book 22, Hadith 322 Next Hadith → "I heard Ibn 'Umar say" "The Prophet used to fast three days of each month.

Sunan an-Nasa'i Book 22, Hadith 324