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 Messenger of Allah (peace and blessings be upon him) and said: "O Messenger of Allah! Allah has saved me only because of truthfulness, and part of my repentance is that I will never tell a lie again, and that I will part with my wealth (by giving it in charity) for Allah, the Mighty and Majestic, 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." He said: "I will keep my share of Khaybar."
Hadith Referenceالمعجم الكبير للطبراني / باب الكاف / 16144