وَالَّذينَ يُتَوَفَّونَ مِنكُم وَيَذَرونَ أَزواجًا يَتَرَبَّصنَ بِأَنفُسِهِنَّ أَربَعَةَ أَشهُرٍ وَعَشرًا ۖ فَإِذا بَلَغنَ أَجَلَهُنَّ فَلا جُناحَ عَلَيكُم فيما فَعَلنَ في أَنفُسِهِنَّ بِالمَعروفِ ۗ وَاللَّهُ بِما تَعمَلونَ خَبيرٌ

Those of you who pass away and leave wives, they should wait alone for four months and ten days. Once they have completed their term, you bear no responsibility for their reasonable decisions. God is fully aware of what you do.