We thought that by this (prolonging the first rak’ah). He (the prophet) meant that the people might join the first rak’ah.
Sunan Abi Dawud Book 2, Hadith 410
← Previous Hadith He would recite Fatihat al-kitab in the last two surahs. Hammam added: He would prolong the first rak’ah but would not prolong the second so much; and he did so similarly in the afternoon prayer, and so in the morning prayer.

Sunan Abi Dawud Book 2, Hadith 409 Next Hadith → We asked Khabbab: Did the Messenger of Allah (ﷺ) recit (the Quran) in the noon and afternoon prayers? He replied: Yes. We then asked: How did you know this? He said: By the shaking of his beard, may peace be upon him.

Sunan Abi Dawud Book 2, Hadith 411