Rashi on Genesis 17:10/רש"י על בראשית י״ז:י׳

1'ביני וביניכם וגו BETWEEN ME AND YOU — “you” is plural and refers to all those belonging to Abraham who were then alive.

2ובין זרעך אחריך AND THY SEED AFTER THEE — those who are yet to be born.

3המול is an infinitive equal to לְהִמּוֹל just as you may say עַשׂוֹת in place of לעשות (i.e. the infinitive may be with or without ל prefixed).