Some of us recited the Tashahhud while they were standing.

Abu Dawud said: Ibn-Zubair made two prostrations before giving the salutation in a similar way when he stood up at the end of two rak’ahs. This is the opinion of al-Zuhrl.
Sunan Abi Dawud Book 2, Hadith 646
← Previous Hadith The Messenger of Allah (ﷺ) led us in prayer praying two rak'ahs. When he stood up and did not sit (at the end of two rak'ahs) the people stood up along with him. When he finished the prayer and we expect him to give the salutation, he said: "Allah is most great." While sitting and made two prostrations before giving the salutation. Then he gave it.

Sunan Abi Dawud Book 2, Hadith 645 Next Hadith → The Prophet (ﷺ) said: When an imam stands up at the end of two rak'ahs , if he remembers before standing straight up, he should sit down, but if he stands straight up, he must not sit down, but perform the two prostrations of forgetfulness.

Abu Dawud said: I have not narrated in this book of mine any hadith from Jabir Al-Ju'fi (one of the narrators) except this one.

Sunan Abi Dawud Book 2, Hadith 647