(Ahsaab) 33 : 32
يَا نِسَاءَ النَّبِيِّ لَسْتُنَّ كَأَحَدٍ مِنَ النِّسَاءِ ۚ إِنِ اتَّقَيْتُنَّ فَلَا تَخْضَعْنَ بِالْقَوْلِ فَيَطْمَعَ الَّذِي فِي قَلْبِهِ مَرَضٌ وَقُلْنَ قَوْلًا مَعْرُوفًا

Oh women of Prophet! You are not like any other women; if you are heedful, you should not speak indecently that those who have disease in the heart will attract you, you talk moderately. 

‘You should not speak indecently’ means you should behave and deal in conscious that Lord Allah is ever watching you, and you should remember that all thoughts, deeds, and even treachery of eyes are being recorded in the book of deed fastened in everyone’s neck, and everyone’s judgment will be done in the Hereafter according to that Book as explained in the verses 17: 13-14. See explanation 9: 71-72; 23: 62-63; 24: 60-61.