Musnad Ahmad 30:864

I read to Abu Qurrah al-Zubaydi, Musa ibn Tariq, from Musa—meaning Ibn Uqbah—from Abu Salih al-Samman and Ata ibn Yasar, or from one of them, from Abu Hurayrah, from the Prophet, may Allah bless him and grant him peace, who said: "Do you love to strive in supplication? Say: 'O Allah, help us to thank You, to remember You, and to worship You well.'"