"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.  

لَقَدْ كَانَتْ صَلاَةُ الظُّهْرِ تُقَامُ فَيَذْهَبُ الذَّاهِبُ إِلَى الْبَقِيعِ فَيَقْضِي حَاجَتَهُ ثُمَّ يَتَوَضَّأُ ثُمَّ يَجِئُ وَرَسُولُ اللَّهِ ﷺ فِي الرَّكْعَةِ الأُولَى يُطَوِّلُهَا  

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.  

عَنِ النَّبِيِّ ﷺ قَالَ كَانَ يُصَلِّي بِنَا الظُّهْرَ فَيَقْرَأُ فِي الرَّكْعَتَيْنِ الأُولَيَيْنِ يُسْمِعُنَا الآيَةَ كَذَلِكَ وَكَانَ يُطِيلُ الرَّكْعَةَ فِي صَلاَةِ الظُّهْرِ وَالرَّكْعَةَ الأُولَى يَعْنِي فِي صَلاَةِ الصُّبْحِ