1)
Why does the Torah use the double expression "Im Shacho'ach Tishkach"?
1.
Rashi (in 11:13): 'Once you begin to forget, you will go on to forget everything'. 1
2.
Seforno: This will occur if Yisrael attribute their successess in the land to their own prowess
1
Rashi: As it states in Megilas Chasidim (or Megilas S'tarim - [It is also a Sifri]) 'If you will abandon Me for one day, I will abandon you for two!' (See Sifsei Chachamim there). In other words, when you forget Hashem, He forgets you
2)
Why does the Torah use the double expression "Ki Avod Toveidun"?