What does Psalm 50:17 mean?

In this psalm, Israel is rebuked by God (Psalm 50:7). While they participate in sacrifices and rituals (Psalm 50:8), God rejects those rites (Psalm 50:9). This passage explains why: their sacraments are hypocritical and insincere. The people's attitudes and behaviors are drastically far from what they ought to be (Psalm 50:16). As the psalm continues, it will further detail how the nation's hearts were sinful, rather than godly (Psalm 50:18–21).

That Israel "casts" God's words aside reflects a sense of disrespect. They do not misunderstand. Nor are they making well-meaning mistakes, nor striving but falling short. The people of Asaph's era (Psalm 50:1) are deliberately ignoring what God has commanded (Psalm 73:2–3; 74:10). Complacency, such as in the New Testament church of Laodicea (Revelation 3:14–15), is harmful enough. The nation addressed by this psalm is intentionally throwing God's will away. Proverbs 29:1 sounds a stern warning to everyone who treats God's words as worthless and rejects His discipline: "He who is often reproved, yet stiffens his neck, will suddenly be broken beyond healing."