דברים ד, לז : וְתַחַת כִי אָהַב אֶת-אֲבֹּתֶיךָ
Baal HaTurim points out that the word "ve'sachas" also appears in Mishpatim (24:10) "ve'sachas raglav ... (and under His feet)", with reference to the Throne of Hakadosh-Baruch-Hu (also known as 'the Chariot').
This teaches us, he explains, that the Avos are synonymous with the Chariot - inasmuch as they uphold G-d's Glory in the world, even today, by virtue of the legacy that they left behind.