Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates from the Prophet (peace and blessings be upon him) that the Messenger of Allah (peace and blessings be upon him) said: "Allah has pardoned my Ummah for mistakes, forgetfulness, and what they were coerced into."
(b) In the narration of al-Rabi' it is that the Messenger of Allah (peace and blessings be upon him) said: "Allah has pardoned for my sake."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الأيمان / 20013