Musnad Ahmad 30:3223

Sulayman ibn Dawud—who is Abu Dawud al-Tayalisi—narrated to us, he said: Hammam narrated to us, he said: Qatadah narrated to us, from al-Nadr ibn Anas, from Bashir ibn Nahik, from Abu Hurayrah, from the Prophet, peace and blessings of Allah be upon him, who said: "Locusts of gold were sent down upon Ayyub, and he began picking them up. So He 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."