Musannaf Ibn Abi Shayba 33:213

Abu Usama narrated to us, from Za'ida, from 'Abd al-Malik ibn 'Umayr, from Rib'i, from Abu Musa, who said: 'Amr ibn al-'As said: "By Allah, if Abu Bakr and 'Umar had left this wealth while something of it was permissible for them, then they would have been cheated and their judgment would have been deficient. And by Allah, they were neither cheated nor were their judgments deficient. And if they were two men for whom it was forbidden to take from this wealth which we have taken after them, then we have perished. And by Allah, the error is only from our side."