What is the covenant mentioned in this Pasuk?
Seforno: If Avraham will go in the ways of Hashem, He will be his G-d, and the G-d of his children 1 whom he will teach to follow in his footsteps.
Gur Aryeh: How does Rashi know that both covenants are intended; perhaps Hashem refers to only one? The word "My covenant" is used without specifying, so we must interpret that the covenant included numerous things.
This also explains why Yehoshua circumcised the entire generation that was born in the desert, before beginning the conquest of Cana'an (Yehoshua 5: 2-9).
Why is the word "Bris" (covenant) mentioned 13 times in this section of the Torah?
Refer to 17:9:1.2.