Musannaf Ibn Abi Shaybah 4140 — People standing when the iqamah

Ibrahim said: The early generations used to dislike that, when the muezzin says "Qad qamat al-salah" (the prayer has been established), the people should stand up while the imam is not present, and that they should wait for the imam standing. And it used to be said that standing in this way is the standing of heedlessness.