Why does the Torah need to write both "Z'chor" and "Al Tishkach"?
Sifra (Bechukosai, 27:3): "Al Tishkach" means to remember it in the heart; "Z'chor", to verbalize it. 1
Seforno: With reference to 9:6:1:1, the Torah is reminding Yisrael how they sinned time and time again, even after they had witnessed Musar of Hashem and His Geatness.
See Torah Temimah, note 1, who elaborates.
What is the meaning of "Mamrim"?
Rashi (Erchin, 15a) Targum Onkelos and Targum Yonasan: It means 'rebels'.
Rashi (in Ki Seitzei, 21:18): It means - 'angered'; (in Melachim 2, 14:26) - 'opposed'; (in Yirmiyah, 4:17) -'troublesome; (in Tehilim, 140:1) - 'warmongers'.
Why does the Torah write "Mamrim Heyisem Im Hashem" and not 'ba'Hashem' or 'Lifnei Hashem' (See Oznayim la'Torah)?