"The Iqamah for Zuhr prayer would be said, and a person could go to the Al-Baqi', relieve himself, perform wudhu, and come (to the masjid), and the Messenger of Allah (ﷺ) would still be in the first rak'ah, making it lengthy.
Sunan an-Nasa'i Book 11, Hadith 98
← Previous Hadith "We were in At-Taff with Anas, and he led them in praying Zuhr. When he had finished, he said: 'I prayed Zuhr with the Messenger of Allah (ﷺ) and he recited two surahs for us in the two rak'ahs: "Glorify the Name of your Lord, the Most High' and 'Has there come to you the narration of the over-whelming (i.e. The Day of Resurrection)?'"

Sunan an-Nasa'i Book 11, Hadith 97 Next Hadith → His father said: "The Messenger of Allah (ﷺ) used to lead us in prayer, and he would recite in the first two rak'ahs and make us hear some verses. And he would make the (first) Rak'ah lengthy in Zuhr, and also the first rak'ah." Meaning in Subh.

Sunan an-Nasa'i Book 11, Hadith 99