وَٱلَّذِينَ يُتَوَفَّوۡنَ مِنكُمۡ وَيَذَرُونَ أَزۡوَٰجٗا يَتَرَبَّصۡنَ بِأَنفُسِهِنَّ أَرۡبَعَةَ أَشۡهُرٖ وَعَشۡرٗاۖ فَإِذَا بَلَغۡنَ أَجَلَهُنَّ فَلَا جُنَاحَ عَلَيۡكُمۡ فِيمَا فَعَلۡنَ فِيٓ أَنفُسِهِنَّ بِٱلۡمَعۡرُوفِۗ وَٱللَّهُ بِمَا تَعۡمَلُونَ خَبِيرٞ

Wallazeena yutawaffawna minkum wa yazaroona azwaajai yatarabbasna bi anfusihinna arba'ata ashhurinw wa 'ashran fa izaa balaghna ajalahunna falaa junaaha 'alaikum feemaa fa'alna feee anfusihinna bilma'roof; wallaahu bimaa ta'maloona Khabeer

If any of you die and leave widows behind, they shall wait concerning themselves four months and ten days: When they have fulfilled their term, there is no blame on you if they dispose of themselves in a just and reasonable manner. And Allah is well acquainted with what ye do.

— Al-Baqarah (ٱلْبَقَرَة), 2:234