He prayed Maghrib at Jam with the Isha prayer with a single iqamah. He then narrated from Ibn Umar that he prayed in the same way, and Ibn Umar reported that the Prophet ﷺ did likewise.
أنه صلى المغرب بجمع والعشاء بإقامة، ثم حدث عن ابن عمر أنه صلى مثل ذلك، وحدث ابن عمر أن النبي ﷺ صنع مثل ذلك.
Muslim narrated it in the Hajj chapter (1288:288), from Muhammad bin Muthanna, who said, Abdul-Rahman bin Mahdi told us, Shubah told us, from Hakam and Salama bin Kuhayl, from Saeed bin Jubayr, who said, then he mentioned it.He also said, Zuhayr bin Harb told me this, saying, Waki told us, Shubah told us, with this same chain, and he said, He prayed them with a single call to prayer.