1. Ramban - M'aseh Avos Siman L'bonim

2. R B'Chaya - 
    a) Avraham expressing ownership by strolling through the land'/ exploring via chachma
    b) Malki Tzedek - Explaining "Cohen" 
    c) "Koneh Shamayim" - explaining "Koneh" 

3. Sforno - "Koneh Shamayim" - explaining "Koneh"