Sahih Muslim , Book 48, Hadith 8 (In-Book) ⓘ

Abu Huraira reported Allah's Messenger as saying: When one of you makes a supplication (to his Lord) one should not say: O Allah, grant me pardon, if Thou so likest, but one should beg one's (Lord) with a will and full devotion, for there is nothing so great in the eye of Allah which He cannot grant.

حَدَّثَنَا يَحْيَى بْنُ أَيُّوبَ، وَقُتَيْبَةُ، وَابْنُ، حُجْرٍ قَالُوا حَدَّثَنَا إِسْمَاعِيلُ، - يَعْنُونَ ابْنَ جَعْفَرٍ - عَنِ الْعَلاَءِ، عَنْ أَبِيهِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ إِذَا دَعَا أَحَدُكُمْ فَلاَ يَقُلِ اللَّهُمَّ اغْفِرْ لِي إِنْ شِئْتَ وَلَكِنْ لِيَعْزِمِ الْمَسْأَلَةَ وَلْيُعَظِّمِ الرَّغْبَةَ فَإِنَّ اللَّهَ لاَ يَتَعَاظَمُهُ شَىْءٌ أَعْطَاهُ ‏" ‏ ‏.‏