All of the commands that were uttered from the mouth of the Almighty reflect His own nature and character. Some of these commandments are instinctive to man while some require His children to employ mental/mathmatical skills in order to do his will and please him. The Sabbath as well as His holy days for instance are commandments that require watchfulness and calculation on the part of the adherent. Remember that the Jesus said (as he quoted the Law of Moses) that we are to love God with all our heart, soul, mind and strength. All of this comes naturally to the one who is born of His spirit.