Musannaf Ibn Abi Shayba 35:323

Ibn Numayr narrated to us, from Sa‘d ibn Sa‘id, from Muhammad ibn Ibrahim al-Taymi, from Qays ibn ‘Amr, who said: The Prophet, may Allah bless him and grant him peace, saw a man praying two rak‘ahs after the morning prayer. The Prophet, may Allah bless him and grant him peace, said, "Is the morning prayer [to be performed] twice?" The man said, "I had not prayed the two rak‘ahs that are before it, so I prayed them now." The Messenger of Allah, may Allah bless him and grant him peace, remained silent.