The Hebrew verb marah (מָרָה) means to be rebellious, contentious, or disobedient. It often occurs in covenantal contexts describing Israel's persistent refusal to heed God's commands and the prophetic word. Appearing about 45 times, it is a key diagnostic term for Israel's spiritual failures in the wilderness and beyond.
Marah frequently appears in the phrase 'they rebelled against me' in the prophets, particularly Ezekiel, where it summarizes centuries of Israelite covenant violation. Unlike accidental sin, marah implies knowing resistance — having heard God's word and choosing to oppose it. This word shows up prominently in the wilderness narratives where a pattern of rebellion against Moses and God is established. Theologically, marah explains why a journey of days stretched into forty years — the rebellious heart prolongs its own exile. The New Testament parallel is hardening the heart against the Holy Spirit (Hebrews 3:15).