Quran 2:240

وَٱلَّذِينَ يُتَوَفَّوۡنَ مِنڪُمۡ وَيَذَرُونَ أَزۡوَٲجً۬ا وَصِيَّةً۬ لِّأَزۡوَٲجِهِم مَّتَـٰعًا إِلَى ٱلۡحَوۡلِ غَيۡرَ إِخۡرَاجٍ۬‌ۚ فَإِنۡ خَرَجۡنَ فَلَا جُنَاحَ عَلَيۡڪُمۡ فِى مَا فَعَلۡنَ فِىٓ أَنفُسِهِنَّ مِن مَّعۡرُوفٍ۬‌ۗ وَٱللَّهُ عَزِيزٌ حَڪِيمٌ۬ ٢٤٠

Those who die and leave wives, a will shall provide their wives with support for a year, provided they stay within the same household. If they leave, you commit no sin by letting them do whatever they wish, so long as righteousness is maintained. ALLAH is Almighty, Most Wise.