Musannaf Ibn Abi Shaybah

Hazrat Muslim says that during the time of Ziyad, I used to sit with Hazrat Masruq and Hazrat Abu Ubaidah. When the time for prayer would come, both of them would stand up and perform the prayer, then sit down again. Then, when the muezzin would give the call to prayer and the imam would come out, they would stand up and perform the prayer with him as well, and they used to do this at the time of Asr.