It is not obvious how Hagar connects with the covenant from Mount Sinai. This is the only time in Scripture that such a statement is made.1 However, given the fact that Sarah is connected with the Abrahamic covenant (Isaiah 51:1–2), one can understand how further reflection would result in Hagar being connected with Moses.
24 Ces faits ont une valeur allégorique; car ces femmes sont deux alliances. L'une du mont Sinaï, enfantant pour la servitude, c'est Agar