A man came on Friday while the Prophet ﷺ was delivering the sermon.The Prophet ﷺ asked, "Have you prayed, so-and-so?"The man replied, "No."The Prophet ﷺ said, "Stand up and pray two units."
حدثنا سليمان بن حرب حدثنا حماد عن عمرو وهو ابن دينار
أن رجلا جاء يوم الجمعة والنبي ﷺ يخطب فقال أصليت يا فلان قال لا قال قم فاركع
Sourced by Bukhari, Friday Prayer, Chapter, "If the imam sees a man arrive while he is delivering the sermon," no. 930, and Muslim, Friday Prayer, Chapter on greeting the mosque while the imam is delivering the sermon, no. 875, from the hadith of Hammad bin Zayd, with the same chain, and so on.