Sunan Abi Dawud — Tribute, Spoils, and Rulership (Kitab Al-Kharaj, Wal-Fai' Wal-Imarah) — Hadith No: 3046
Translation
Narrated Ubaydullah: Harb ibn Ubaydullah told on the authority of his grandfather, his mother's father, that he had it on the authority of his father that the Messenger of Allah (ﷺ) said: Tithes are to be levied on Jews and Christians, but not on Muslims