عَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ عَنِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ قَالَ إِذَا تَمَنَّى أَحَدُكُمْ فَلْيَنْظُرْ مَا الَّذِي يَتَمَنَّى فَإِنَّهُ لَا يَدْرِي مَا الَّذِي يُكْتَبُ لَهُ مِنْ أُمْنِيَّتِهِ
It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: When any one of you begins to wish for something, he should reflect upon his wish, because he does not know which part of his wish is written for him.