The Hebrew of Genesis 16:3 marks the moment with a small, precise number: after Abram had dwelt ten years in the land of Canaan. Targum Pseudo-Jonathan holds onto that ten and adds the other detail the earlier verse had already promised — Sarah set her free, and only then gave her to Abraham as a wife.
Ten years is not a round literary number here. It is a halakhic marker. Later rabbinic law would read this verse as the source for the rule that a couple who remain childless for ten years in the Land of Israel must reconsider how to build their household. Ten years of waiting is the patience Sarah has paid before she acts.
The Targum also underscores what kind of marriage this is. It is not a concubinage. Sarah formally manumits Hagar — the Mizreitha, the Egyptian woman — and gives her to Abraham to wife. The vocabulary is elevated. Whatever sorrow follows, Hagar does not enter Abraham's tent as chattel.
The Maggid hears two things in this verse. First, that holy households still operate by law and by calendar; ten years in Canaan is not a shrug but a decision (Genesis 16:3). Second, that the way people are brought into a covenant family matters — freedom first, marriage second, motherhood third. Sarah gets the order right, even when the outcome will not be what she hoped.