Musnad Abu Ya'la al-Mawsili 152:3

'Abd al-Ghaffar narrated to us, 'Ali ibn Mushir narrated to us, from al-A'mash, from Shaqiq, from 'Abdullah ibn Mas'ud, who said: A man said, "O Messenger of Allah, shall we be held accountable for what we did during the Jahiliyyah (pre-Islamic period)?" He said, "Whoever does good in Islam shall not be held accountable for what he did during the Jahiliyyah, and whoever does evil in Islam shall be held accountable for the first and the last."