Why does it say both "u'Shmatem b'Kolo v'Lo Samru"?
Malbim: "U'Shmatem b'Kolo" is fulfilling Mitzvos Aseh. "V'Lo Samru" is not transgressing Lavim.
What is the meaning of "vi'Hyisem"?
Rashi: [You and your king] will last many days.
What is the meaning of "vi'Hyisem? Achar Hashem Elokeichem"?
Mahari Kara: You will follow Hashem and His words. 1
Malbim: Hashem will be in front of you, to fight for you and save you, and the king will be in back of Him, like a chief general following his appointment; he will be an intermediary between Hashem and you.
Mahari Kara: If so, the verse did not promise any reward for this! It is better to say that the verse promises long life.
