Musnad Abu Ya'la al-Mawsili 160:2

'Amr al-Naqid narrated to us, Hushaym narrated to us, Abu Bishr—meaning Ja'far ibn Iyas—narrated to us, from Shahr ibn Hawshab, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever it pleases that Allah should answer him during hardships and distress, let him increase supplication during times of ease."