It is narrated from Hazrat Saeed bin Musayyib (may Allah have mercy on him), and he was asked about the person who prays in only one shirt and does not have an izar (lower garment) on his body. He replied that there is no harm in it as long as it covers the awrah. This is the statement of Amr bin Shu'aib. While Bukair says, Hazrat Saeed bin Musayyib (may Allah have mercy on him) said that Sayyiduna Ibn Mas'ud (may Allah be pleased with him) said, "Indeed, we used to pray in only one garment until Allah Almighty granted us plenty of clothes. Then he said, 'Pray in two garments only.'" So Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him) said, "There is no harm in it. We used to pray in only one garment during the blessed era of the Messenger of Allah (peace and blessings be upon him), even though we had two garments." Then it was presented to Sayyiduna Umar bin Khattab (may Allah be pleased with him), and he was with them. "Will you not decide among these gentlemen?" He replied, "I am with my (position)."