Sayyiduna Abu Hurayrah (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "Allah has pardoned my Ummah for the whisperings that arise in a person's heart and mind, as long as he does not speak them with his tongue or act upon them."
(b) In the narration of Hisham, the Prophet (peace and blessings be upon him) said: "Allah has pardoned my Ummah."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 14195