The Greek verb gongyzo means to grumble, murmur, or complain in a low voice — especially about God's provision or leadership. The word is onomatopoeic, mimicking the low sound of discontent. It appears in the Septuagint for Israel's wilderness grumbling and in the Gospels and Paul's letters for ongoing spiritual murmuring.
Gongyzo is consistently presented as sin in Scripture. In the wilderness, Israel murmured against Moses, God's provision, and ultimately God Himself — provoking judgment (Numbers 14:2; 1 Corinthians 10:10). In John 6, the crowd murmurs at Jesus' bread of life discourse, refusing to receive what only God could give. Paul warns explicitly: 'Do not grumble, as some of them did — and were killed by the destroying angel' (1 Corinthians 10:10). Philippians 2:14 counters: 'Do everything without grumbling.' The theology of gongyzo is that murmuring is ingratitude crystallized — it refuses to trust God's goodness.