“You must fear Hashem your G-d” (Devarim 10,20)
It is a positive commandment that the fear of Hashem should be constantly in our consciousness so that we should not sin. That is to say, that we should fear His punishment, and our heart should not be without fear of Him all day, and about this it says “You must fear Hashem your G-d”.
The root of the commandment of fear of Hashem, may He be blessed, is obvious to those who can see light, for the greatest protection against sin is the fear of punishment.
This commandment applies in every place at every time, to both men and women and it is one of the commandments which is continually incumbent upon a person, whose obligation does not cease upon a person forever, not for one minute. When the opportunity to do a sin comes to hand, a person is obligated to rouse his spirit and concentrate his heart on this chapter, that Hashem, may He be blessed, is watching over all the actions of mankind, and He will pay them back according to the evilness of the action. One who does not turn his heart towards this thought at that time transgresses this positive commandment for that is the time when a person is obligated to fulfil this commandment. Even so, all a person’s days and all seasons are included in this commandment, for this purpose, so he should be diligent and remember it.