وَعَنْ عَائِشَةَ قَالَتْ: إِنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ إِذَا جَلَسَ مَجْلِسًا أَوْ صَلَّى تكلَّم بِكَلِمَاتٍ فَسَأَلْتُهُ عَنِ الْكَلِمَاتِ فَقَالَ:" إِنْ تُكُلِّمَ بِخَيْرٍ كَانَ طَابَعًا عَلَيْهِنَّ إِلَى يَوْمِ الْقِيَامَةِ وَإِنْ تُكُلِّمَ بِشَرٍّ كَانَ كَفَّارَةً لَهُ: سُبْحَانَكَ اللَّهُمَّ وَبِحَمْدِكَ لَا إِلَهَ إِلَّا أَنْتَ أَسْتَغْفِرُكَ وَأَتُوبُ إِلَيْكَ ". رَوَاهُ النَّسَائِيّ

Qatada told of hearing that when God’s messenger saw the new moon he said, “A new moon of good and right guidance; a new moon of good and right guidance; a new moon of good and right guidance. I believe in Him who created you” (three times). He would then say, “Praise be to God who has made such and such a month to pass and has brought such and such a month.” Abu Dawud transmitted it.