Abu Hurayra reported that the Messenger of Allah, may Allah bless him and grant him peace, said, "When one of you makes a supplication, he should not say, 'If you wish.' He should be firm in asking and he should have great hope. Allah does not think that anything that He gives is too great.'"  

أَنَّ رَسُولَ اللهِ ﷺ قَالَ إِذَا دَعَا أَحَدُكُمْ فَلاَ يَقُولُ إِنْ شِئْتَ وَلْيَعْزِمِ الْمَسْأَلَةَ وَلْيُعَظِّمِ الرَّغْبَةَ فَإِنَّ اللَّهَ لاَ يَعْظُمُ عَلَيْهِ شَيْءٌ أَعْطَاهُ  

Anas reported that the Messenger of Allah, may Allah bless him and grant him peace, said, "When one of you makes a supplication, he should be firm in the supplication and not say, 'O Allah, if you like, give to me.' Allah cannot be forced against His will."  

قَالَ رَسُولُ اللهِ ﷺ إِذَا دَعَا أَحَدُكُمْ فَلْيَعْزِمْ فِي الدُّعَاءِ وَلاَ يَقُلِ اللَّهُمَّ إِنْ شِئْتَ فَأَعْطِنِي فَإِنَّ اللَّهَ لاَ مُسْتَكْرِهَ لَهُ