Musnad Abu Ya'la al-Mawsili 248:20

Mukhlad ibn Abi Zumayl narrated to us, Ubayd Allah ibn Amr narrated to us, from Abd al-Malik ibn Umayr, from Jabir ibn Samurah, who said: A man asked the Prophet, peace and blessings of Allah be upon him, "Should I pray in the garment in which I come to my wife?" He said, "Yes, unless you see something on it, then wash it."