Sunan Abi Dawud — Tribute, Spoils, and Rulership (Kitab Al-Kharaj, Wal-Fai' Wal-Imarah) — Hadith No: 3048
Translation
A man reported from Bakr bin Wa’il on the authority of his maternal uncle as saying, I said “Apostle of Allaah(ﷺ) may I levy tithe on my people.?” He replied “Tithes are to be levied on Jews and Christians.”