وَالْقَوَاعِدُ مِنَ النِّسَاۤءِ الّٰتِيْ لَا يَرْجُوْنَ نِكَاحًا فَلَيْسَ عَلَيْهِنَّ جُنَاحٌ اَنْ يَّضَعْنَ ثِيَابَهُنَّ غَيْرَ مُتَبَرِّجٰتٍۢ بِزِيْنَةٍۗ وَاَنْ يَّسْتَعْفِفْنَ خَيْرٌ لَّهُنَّۗ وَاللّٰهُ سَمِيْعٌ عَلِيْمٌ ( النور: ٦٠ )
Walqawaa'idu minan nisaaa'il laatee laa yarjoona nikaahan falisa 'alaihinna junaahun ai yada'na siyaabahunna ghaira mutabar rijaatim bizeenah; wa ai yasta'fifna khairul lahunn; wallaahu Samee'un 'Aleem (an-Nūr 24:60)
Sahih International:
And women of post-menstrual age who have no desire for marriage – there is no blame upon them for putting aside their outer garments [but] not displaying adornment. But to modestly refrain [from that] is better for them. And Allah is Hearing and Knowing. (An-Nur [24] : 60)
1 Mufti Taqi Usmani
And those old women who have no hope for marriage, there is no sin on them, if they take off their (extra) clothes while they do not display their adornment. Still, that they refrain (even from this) is better for them. Allah is All-Hearing, All-Knowing.