When Hazrat Mu'adh bin Jabal (may Allah be pleased with him) arrived in the land of Shaam, he found out that the people of Shaam did not perform Witr. He asked Hazrat Amir Mu'awiyah (may Allah be pleased with him), "What is the reason that I do not see the people of Shaam performing Witr?" Hazrat Amir Mu'awiyah (may Allah be pleased with him) asked, "Is it obligatory upon them?" Hazrat Mu'adh (may Allah be pleased with him) replied, "Yes! I heard the Noble Prophet (peace and blessings be upon him) say: 'My Lord has added one prayer for me, and it is Witr, the time of which is between the 'Isha prayer and the rising of Fajr.'"