Gideon places Jether in an awkward position. Jether may demonstrate his own maturity and nobility [by Canaanite standards] in defense of the [royal?] house and become an accomplice in his father’s personal vendetta, or he may disobey his father and prove himself unmanly.
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20 So he said to Jether his firstborn, “Rise and kill them!” But the young man did not draw his sword, for he was afraid, because he was still a young man.