Musnad Ahmad 33:312

Yahya narrated to us, from Hisham—and [likewise] Abd al-Wahhab al-Khaffaf narrated to us, from Hisham—from Yahya ibn Abi Kathir, from Ubayd Allah ibn Miqsam, from Jabir, who said: A funeral procession passed by us, and the Messenger of Allah (may Allah bless him and grant him peace) stood up for it, and we stood up with him. I said: "O Messenger of Allah, it is the funeral of a Jew." He said: "Indeed, death is a source of alarm, so when you see a funeral, stand up."