Awn Azdi says that Umar bin Ubaidullah bin Ma'mar, "who was the governor of Fars," wrote a letter to Sayyiduna Ibn Umar (may Allah be pleased with them both), in which he asked him about prayer. Sayyiduna Ibn Umar (may Allah be pleased with them both) replied in writing that when the Prophet (peace and blessings be upon him) would leave his house, he would only perform two rak'ahs until he returned (meaning the shortened prayer).