Sunan An-Nasa'i

Abdur-Rahman bin Ka'b bin Malik narrated that 'Abdullah bin Ka'b said:""I heard Ka'b bin Malik narrating his Hadith about when he stayed behind and did not join the Messenger of Allah on the campaign to Tabuk. He said: 'When I sat down before him I said: ""O Messenger of Allah, as part of my repentance I want to give my wealth in charity to Allah and His Messenger."" The Messenger of Allah said: ""Keep some of your wealth for yourself; that is better for you."" I said: ""I will keep my share that is in Khaibar