Musnad Ahmad

It is narrated from Hazrat Anas (may Allah be pleased with him) that when the Prophet (peace and blessings be upon him) arrived in Madinah Munawwarah, he stayed in the upper part of Madinah in the neighborhood of Banu Amr bin Awf and remained there for fourteen nights. Then he sent for the chiefs of Banu Najjar. They came with their swords hanging by their sides. That scene is still before my eyes: the Prophet (peace and blessings be upon him) was on his mount, Hazrat Abu Bakr Siddiq (may Allah be pleased with him) was behind him, and Banu Najjar were around them, until the Prophet (peace and blessings be upon him) reached the courtyard of Hazrat Abu Ayyub Ansari (may Allah be pleased with him). In the beginning, wherever the time for prayer occurred, the Prophet (peace and blessings be upon him) would pray there, even in a goat enclosure. Then the Prophet (peace and blessings be upon him) ordered a mosque to be built and called the people of Banu Najjar and said to them, "O Banu Najjar! Settle the price of this garden with me." They replied, "We will take its price only from Allah." At that time, there were some graves of polytheists, a wasteland, and a tree there. At the command of the Prophet (peace and blessings be upon him), the graves of the polytheists were dug up, the wasteland was leveled, and the tree was cut down. A tree was planted towards the qiblah side of the mosque, and the doors were made of stone. People would hand bricks to the Prophet (peace and blessings be upon him), and the Prophet (peace and blessings be upon him) would say, "O Allah! The real life is the life of the Hereafter. O Allah! Help the Ansar and the Muhajirin." It is narrated from Hazrat Anas (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said, "When any one of you comes for prayer, he should walk calmly. Whatever part of the prayer he catches, he should pray, and whatever he misses, he should complete it (afterwards)."