مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3046
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Ibn 'Abbas (رضي الله عنه) said: The Messenger of Allah (ﷺ) said: "Good dreams are one of the seventy parts of Prophethood."
Musnad Ahmad 3071Saheeh, because of corroborating evidence]