Sahih al-Bukhari 4810
Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh))
The Statement of Allah the Most High: Say: "O 'Ibādi (My slaves) who have transgressed against themselves (by committing evil deeds and sins)! Despair not of the Mercy of Allah..." (V39:53)
Narrated Ibn `Abbas: Some pagans who committed murders in great number and committed illegal sexual intercourse excessively, came to Muhammad and said, "O Muhammad! Whatever you say and invite people to, is good: but we wish if you could inform us whether we can make an expiration for our (past evil) deeds." So the Divine Verses came: 'Those who invoke not with Allah any other god, not kill such life as Allah has forbidden except for just cause, nor commit illegal sexual intercourse.' (25:68) And there was also revealed:-- 'Say: O My slaves who have transgressed against their souls! Despair not of the Mercy of Allah.' (39:53)