Mukhtasar Bukhari

Narrated from Sayyiduna Abdullah bin Malik bin Buhaina (may Allah be pleased with him), who belonged to the tribe of Azd: The Messenger of Allah (peace and blessings be upon him) saw a man performing two (2) rak‘ahs of prayer after the iqamah had been pronounced. When the Messenger of Allah (peace and blessings be upon him) finished (the prayer), the people gathered around that man. The Messenger of Allah (peace and blessings be upon him) said to him: "Are there four rak‘ahs in the morning prayer? Are there four rak‘ahs in the morning prayer?"