Musnad Abu Ya'la al-Mawsili 160:101

And with his chain of narration, that the Messenger of Allah (may Allah bless him and grant him peace) said: "When one of you supplicates, let him not say: 'O Allah, forgive me if You will.' Rather, let him be resolute and let him make the desire great, for indeed, nothing that Allah the Almighty gives is too great for Him."