مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3150
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated from Ibn 'Abbas (رضي الله عنه) that The Prophet (ﷺ) was praying and a lamb wanted to pass in front of the Prophet (ﷺ) and he started stepping forwards and backwards, trying to stop it, al-Hajjaj said: He kept trying to stop it until the lamb went away.
Musnad Ahmad 3174A Saheeh hadeeth; its isnad is interrupted]