Saying ‘if only’ opens the door to Satan

The Messenger of Allah ﷺ said: "The strong believer is better and more beloved to Allah ﷻ than the weak believer, and there is good in everything. Be eager for what benefits you, seek help from Allah ﷻ, and do not be helpless. If something befalls you, do not say, ‘If only I had done such-and-such, it would have been such-and-such’; rather say, ‘It is the decree of Allah ﷻ, and whatever He willed, He did,’ for ‘if only’ opens the work of Satan."

قَالَ رَسُولُ اللَّهِ ﷺ: «الْمُؤْمِنُ الْقَوِيُّ خَيْرٌ وَأَحَبُّ إِلَى اللَّهِ مِنَ الْمُؤْمِنِ الضَّعِيفِ، وَفِي كُلٍّ خَيْرٌ. احْرِصْ عَلَى مَا يَنْفَعُكَ، وَاسْتَعِنْ بِاللَّهِ، وَلاَ تَعْجِزْ. وَإِنْ أَصَابَكَ شَىْءٌ فَلاَ تَقُلْ: لَوْ أَنِّي فَعَلْتُ كَانَ كَذَا وَكَذَا، وَلَكِنْ قُلْ: قَدَرُ اللَّهِ وَمَا شَاءَ فَعَلَ؛ فَإِنَّ لَوْ تَفْتَحُ عَمَلَ الشَّيْطَانِ».