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.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِذَا دَعَا أَحَدُكُمْ فَلاَ يَقُلِ اللَّهُمَّ اغْفِرْ لِي إِنْ شِئْتَ وَلَكِنْ لِيَعْزِمِ الْمَسْأَلَةَ وَلْيُعَظِّمِ الرَّغْبَةَ فَإِنَّ اللَّهَ لاَ يَتَعَاظَمُهُ شَىْءٌ أَعْطَاهُ  

[Machine] The Prophet ﷺ said, "When one of you supplicates to Allah, let him not say, 'O Allah, if You will' rather, let him emphasize his desire, for indeed, Allah does not feel any reluctance in giving what He has promised."  

عَنِ النَّبِيِّ ﷺ أَنَّهُ قَالَ إِذَا دَعَا أَحَدُكُمْ فَلَا يَقُولَنَّ اللهُمَّ إِنْ شِئْتَ وَلَكِنْ لِيُعْظِمْ رَغْبَتَهُ فَإِنَّ اللهَ ﷻ لَا يَتَعَاظَمُ عَلَيْهِ شَيْءٌ أَعْطَاهُ  

[Machine] The translation of the given phrase in English is: "Indeed the Messenger of Allah ﷺ said, 'When one of you supplicates, let him have great desire and hope, for indeed there is nothing too great for Allah.'"  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ «إِذَا دَعَا أَحَدُكُمْ فَلْيُعْظِمِ الرَّغْبَةَ فَإِنَّهُ لَا يَتَعَاظَمُ عَلَى اللَّهِ شَيْءٌ»  

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. (Using translation from Muslim 2679a)   

"إِذا دَعَا أحَدُكمْ فلا يقلْ: اللهمّ اغفرْ لي إنْ شئتَ وليعَزِمْ المسألةَ وليُعظمْ الرغبةَ فإِن اللهَ لَا يعظمُ عليه شيءٌ أعطاهُ".