The Prophet (ﷺ) stood up for a funeral (to show respect) and thereafter he sat down.
Sunan Abi Dawud Book 21, Hadith 87
← Previous Hadith We were with the Prophet (ﷺ) when a funeral passed hi and he stood up for it. When we went to carry it, we found that it was a funeral of a Jew. We, therefore said: Messenger of Allah, this is the funeral of a Jew. He said: Death is fearful event, so when you see a funeral, stand up.

Sunan Abi Dawud Book 21, Hadith 86 Next Hadith → The Messenger of Allah (ﷺ) used to stand up for a funeral until the corpse was placed in the grave. A learned Jew (once) passed him and said: This is how we do. The Prophet (ﷺ) sat down and said: Sit down and act differently from them.

Sunan Abi Dawud Book 21, Hadith 88