It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "A believer does not commit treachery (with the spoils)."
Hadith Referenceالمعجم الأوسط / باب الألف / 275
Hadith Takhrij«أخرجه الطبراني فى «الكبير» برقم: 11578»