Musnad Ahmad 30:919

Abu Dawud narrated to us, Hammam narrated to us, from Qatadah, from An-Nadr—meaning Ibn Anas ibn Malik—from Bashir ibn Nahik, from Abu Hurairah, from the Prophet (peace be upon him), who said: "Locusts of gold were sent down upon Ayyub (Job), and he began to gather them. So [Allah] said: 'Have I not made you rich enough, O Ayyub?' He said: 'O Lord, and who can ever be satisfied with Your mercy?' Or he said: '...with Your bounty.'"