He, sallallaahu ‘alayhi wa sallam, taught them how to seek refuge in Allah from evil:
Aa’ishah (the wife of the Prophet) narrated:
‘ ‘The Messenger of Allah, sallallaahu ‘alayhi wa sallam, took me by my hand (one night) and pointed to the moon and said: “O ‘Aa’ishah, seek refuge in Allah from this, for it is what is meant by the saying Allah (which means): «And from the evil of darkness when it settles.» [Quran: 113:3]”’
Ibn Katheer (a scholar) said: “The reason he, sallallaahu ‘alayhi wa sallam, commanded her to seek refuge from the darkness of the night is that evil usually spreads during it. There is another narration which specified it to the moon, which does not contradict this verse, because the moon is the sign by which night is recognized and it only appears during it (night).”
This narration shows how keen he was on teaching his wives, by taking her by the hand, showing her what he wanted to teach her and then asking her to perform an action based on this knowledge while explaining the reason behind it.