Musnad Ahmad 1119:18

Abu al-Mughirah narrated to us, he said: Safwan narrated to us, he said: Abd al-Rahman ibn Jubayr ibn Nufayr narrated to me, from his father Jubayr, from Awf ibn Malik al-Ashja‘i, who said: We went on an expedition to the border of al-Sham, and Khalid ibn al-Walid was appointed over us. He said: A man from the reinforcements of Himyar joined us. He came to our camp having nothing with him except a sword; he had no weapon other than it. A man from the Muslims slaughtered a camel, and he [the Himyari] kept maneuvering until he took a piece of its hide like a shield, spread it on the ground, and lit a fire over it until it dried. He then made a handle for it, like a buckler. It was decreed that we met our enemy, among whom were mixtures of Romans and Arabs from Quda‘a. They fought us a fierce battle. Among the people was a man from the Romans on a sorrel horse of his, with a gilded saddle, a belt stained with gold, and a sword like that. He kept charging at the people and inciting them. That reinforcement man kept maneuvering for that Roman until he passed by him, so he followed him from behind and struck the tendon of his horse with the sword, and it fell. Then he followed it up by striking him with the sword until he killed him. When Allah granted the victory, he came asking for the spoils, and the people testified for him that he was his killer. Khalid gave him some of his spoils and withheld the rest. When he returned to the camp of Awf, he mentioned it to him. Awf said to him: "Go back to him so he may give you what remains." He went back to him, but he refused him. Awf walked until he came to Khalid and said: "Do you not know that the Messenger of Allah (peace and blessings of Allah be upon him) decreed the spoils for the killer?" He said: "Yes." He said: "Then what prevents you from giving him the spoils of his victim?" Khalid said: "I considered it too much for him." Awf said: "If I see the face of the Messenger of Allah (peace and blessings of Allah be upon him), I will certainly mention that to him." When he arrived in Medina, Awf sent him, and he sought judgment from the Prophet (peace and blessings of Allah be upon him). He summoned Khalid, and Awf was sitting. The Messenger of Allah (peace and blessings of Allah be upon him) said: "What prevents you, O Khalid, from giving this man the spoils of his victim?" He said: "I considered it too much for him, O Messenger of Allah." He said: "Give it to him." He said: He passed by Awf, and Awf pulled his garment and said: "Have I fulfilled for you what I mentioned to you from the Messenger of Allah (peace and blessings of Allah be upon him)?" The Messenger of Allah (peace and blessings of Allah be upon him) heard him and became angry. He said: "Do not give it to him, O Khalid. Will you not leave my commanders alone? Your example and theirs is like a man who bought camels and sheep, then tended to them, then waited for the time of their watering and brought them to a trough. They entered it and drank the clear water, and left its murky part. So the clear part of their affair is for you, and the murky part is upon them."