Sunnan Abu Dawud Collection: ::Book Number 19:: Hadith # 3019
Narrated Jabir ibn Abdullah: Wahb said: I asked Jabir about the condition of Thaqif when they took the oath of allegiance. He said: They stipulated to the Prophet (peace_be_upon_him) that there would be no sadaqah (i.e. zakat) on them nor Jihad (striving in the way of Allah). He then heard the Prophet (peace_be_upon_him) say: Later on they will give sadaqah (zakat) and will strive in the way of Allah when they embrace Islam.