the Prophet said: "Fast the Day of Arafah, for indeed I anticipate that Allah will forgive (the sins) of the year after it, and the year before it."
Jami` at-Tirmidhi Book 8, Hadith 68
← Previous Hadith "I asked - or; the Prophet was asked - about fasting daily. So he said: 'Your family has a right over you.' Then he said: 'Fast Ramadan and that which is after it, and every Wednesday and Thursday. If you do that, then you will have fasted daily, as well as broken (the fast).'"

Jami` at-Tirmidhi Book 8, Hadith 67 Next Hadith → "The Prophet broke (the fast) of Arafah, Umm Fadl sent him some milk to drink."

Jami` at-Tirmidhi Book 8, Hadith 69