Messenger of Allah (saas) said: "No one among you should say: "O Allah, forgive me if You will.' Let him be definite in his asking, and no one can compel Allah."  

قَالَ رَسُولُ اللَّهِ ﷺ لاَ يَقُولَنَّ أَحَدُكُمُ اللَّهُمَّ اغْفِرْ لِي إِنْ شِئْتَ وَلْيَعْزِمْ فِي الْمَسْأَلَةِ فَإِنَّ اللَّهَ لاَ مُكْرِهَ لَهُ