Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Bukhari :: Book 5 :: Volume 59 :: Hadith 364
Narrated Anas bin Malik:
Some people used to allot some date palm trees to the Prophet as gift till he conquered Banu Quraiza and Bani An-Nadir, where upon he started returning their date palms to them.