Musnad Abu Ya'la al-Mawsili 154:141

Abu Khaythama narrated to us, Waki' narrated to us, Shu'bah narrated to us, from al-Hakam and Salamah ibn Kuhayl, from Sa'id ibn Jubayr, from Ibn 'Umar: That he performed them [the two prayers] with a single iqamah. And he said: "This is how the Messenger of Allah, may Allah bless him and grant him peace, did in this place."