Judges Jdg 6:11–16; 1 Sam 16:1–13; Mat 20:16
If the Torah instituted firstborn privilege, the narrative repeatedly elevated the youngest. Isaac, Jacob, Joseph, Ephraim, Gideon, David. But Saul said the same thing Gideon did and was rejected. Smallness vocabulary is not the qualifier. Election is. When Jesus said 'the last will be first,' he was summarizing a pattern the canon had been running since Genesis.
Genesis Gen 48:13–20; Psa 89:27; Col 1:15–18
The Torah instituted firstborn privilege: double portion, consecration to YHWH, the priestly role. The narrative then overturned that privilege six times — Cain to Abel, Ishmael to Isaac, Esau to Jacob, Manasseh to Ephraim, Reuben to Joseph-and-Judah, Jesse's older sons to David. Psalm 89 reframed the word itself: 'I will make him my firstborn.' The New Testament finished the sentence.