Sunan Abi Dawud The Office of the Judge (Kitab Al-Aqdiyah) Abu Hurairah Bashyr bin Ka'b bin Aby بشير بن كعب بن أبي Muslim bin Ibrahim al-Azdy مسلم بن إبراهيم الأزدي الفراهيدي Qatada قتادة Da'if I intended to go (on expedition) to Khaybar. So I came to the Holy Prophet (ﷺ), greeted him and said: I am intending to go to Khaybar. He said: When you come to my agent, you should take from him fifteen wasqs (of dates). If he asks you for a sign, then place your hand on his collar-bone. https://parallelquran.com/hadith/sunan-abi-dawud-3632/