It is narrated from Sayyiduna Ka'b bin Malik (may Allah be pleased with him) that when Allah accepted his repentance, he came to the Prophet (peace and blessings be upon him) and said: "O Messenger of Allah! Allah has saved me because of speaking the truth, and part of my repentance is that I will never tell a lie again, and that I give all my wealth in charity in the way of Allah and His Messenger." The Messenger of Allah (peace and blessings be upon him) said: "Keep some of your wealth with you; that is better for you." Ka'b (may Allah be pleased with him) said: So I kept my share of Khaybar with me.
Hadith Referenceالمعجم الكبير للطبراني / باب الكاف / 16149