مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3262
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated from ‘Ata’ that Ibn az-Zubair prayed Maghrib and said salam after two rak'ahs, and he got up to touch the Black Stone, and the people said Subhanallah, He said: What is the matter with you? Then he prayed the rest and did the two prostrations (of forgetfulness). That was mentioned to Ibn 'Abbas (رضي الله عنه) and he said: He never drifted away from the Sunnah of his Prophet (ﷺ).
Musnad Ahmad 3285A saheeh hadeeth; this is a da'eef isnad]