Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates from the Prophet (peace and blessings be upon him): "For a Muslim, the name of Allah is sufficient. If he forgets to mention the name of Allah while slaughtering, let him mention the name of Allah when eating and eat it (that is, let him say Bismillah and eat)."
He narrated it thus as marfu' (attributed to the Prophet), while others narrated it from Amr bin Dinar, from Jabir bin Zayd, from 'Ayn, who is Ikrimah, from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) as mawquf (his own statement).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيد والذبائح / 18890