Musnad Ahmad 30:2772

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, he said: I heard al-'Ala' narrating from his father, from Abu Hurayrah, from the Prophet, may Allah bless him and grant him peace, that he said: "When one of you supplicates, let him not say: 'O Allah, if You will,' but let him make his desire great, for nothing that Allah, the Mighty and Majestic, gives is too great for Him."