مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3161
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
I read this hadeeth to 'Abdur-Rahman and he said: I came riding on a female donkey, and at that time I had reached puberty, when The Messenger of Allah (ﷺ) was leading the people in prayer. I passed in front of part of the row, then I dismounted and let the donkey loose, and I joined the row. And no one rebuked me for that.
Musnad Ahmad 3185lts isnad is saheeh]