Charles Ellicott Commentary Judges 9:18

"and ye are risen up against my father`s house this day, and have slain his sons, threescore and ten persons, upon one stone, and have made Abimelech, the son of his maid-servant, king over the men of Shechem, because he is your brother);" — Judges 9:18 (ASV)

Seventy persons. —See Note on Judges 9:5.

The son of his maidservant. —The term is intentionally contemptuous. It seems clear from Judges 8:31; Judges 9:1, that she was not a slave, but even of high birth among the Canaanites.