مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2127
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Ibn 'Abbas (رضي الله عنه) said: The iqamah was given for Fajr prayer and a man stood up to pray the two rak'ahs. The Messenger of Allah (ﷺ) took hold of his garment and said: "Are you praying Fajr with four rak'ahs?"
Musnad Ahmad 2130Its isnad is hasan]