Musnad Ahmad 499:1

Yahya ibn Adam narrated to us, Mufaddal ibn Muhalhal narrated to us, from Mughirah, from Shibak, from al-Sha’bi, from a man from Thaqif, who said: We asked the Messenger of Allah (peace and blessings of Allah be upon him) for three things, but he did not grant us a concession. We said: "Our land is a cold land," and we asked him to grant us a concession regarding purification (using cold water), but he did not grant us a concession. We asked him to grant us a concession regarding the *duba* (gourd vessels for drinks), but he did not grant us a concession regarding it for a moment. We asked him to return Abu Bakrah to us, but he refused and said: "He is a freedman of Allah and a freedman of His Messenger." Abu Bakrah had come out to the Prophet (peace and blessings of Allah be upon him) when he was besieging Ta'if and accepted Islam.