Sahih al-Bukhari 7402
Oneness, Uniqueness of Allah (Tawheed)
Adh-Dhat, His Qualities and His Names
Narrated Abu Huraira: Allah's Messenger (ﷺ) sent ten persons to bring the enemy's secrets and Khubaib Al-Ansari was one of them. 'Ubaidullah bin 'Iyad told me that the daughter of Al-Harith told him that when they gathered (to kill Khubaib Al Ansari) he asked for a razor to clean his pubic region, and when they had taken him outside the sanctuary of Mecca in order to kill him, he said in verse, "I don't care if I am killed as a Muslim, on any side (of my body) I may be killed in Allah's Cause; for that is for the sake of Allah's very Self; and if He will, He will bestow His Blessings upon the torn pieces of my body." Then Ibn Al-Harith killed him, and the Prophet (ﷺ) informed his companions of the death of those (ten men) on the very day they were killed.