مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2973
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Ibn 'Abbas (رضي الله عنه) said: A man asked the Prophet (ﷺ) about Hajj, was it every year? He said: "Every Muslim has to do one Haji. If I said every year, then it would become (obligatory).”
Musnad Ahmad 2996A saheeh hadeeth; this is a da’eef isnad]