It is narrated from Hazrat Abu Saeed Khudri (may Allah be pleased with him) that once a funeral procession passed by Marwan, but he did not stand up. Hazrat Abu Saeed (may Allah be pleased with him) said that a funeral had passed by the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) stood up. Upon this, Marwan also had to stand up.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 11437