Anas bin Sirin reported,

I was with Ibn Umar at Arafat. When he set out, I went with him until he reached the imam, prayed the noon and afternoon prayers with him, and then stood with him along with some of my companions until the imam departed. We departed with him until we reached the narrow pass before the two mountain defiles. He made his camel kneel, and we made ours kneel as well, thinking he intended to pray.His servant, who was holding his mount, said, "He does not intend to pray. Rather, he recalled that when the Prophet ﷺ reached this spot, he relieved himself, and so he wishes to do the same."

Ahmad 6151

Sahih

حدثنا يزيد بن هارون أخبرنا عبد الملك

عن أنس بن سيرين قال

كنت مع ابن عمر بعرفات فلما كان حين راح رحت معه حتى أتى الإمام فصلى معه الأولى والعصر ثم وقف معه وأنا وأصحاب لي حتى أفاض الإمام فأفضنا معه حتى انتهينا إلى المضيق دون المأزمين فأناخ وأنخنا ونحن نحسب أنه يريد أن يصلي فقال غلامه الذي يمسك راحلته إنه ليس يريد الصلاة ولكنه ذكر أن النبي ﷺ لما انتهى إلى هذا المكان قضى حاجته فهو يحب أن يقضي حاجته

أحمد 6151صحيح
Contents
Reference
Commentary
Ayat
Collection
Musnad Ahmad
Book
Abdullah bin Umar
Numbering
Darussalam 6151
Ahmad 6151