Word of Truth

You speak a word of power, disrupting the ability of a creature you can see within range to deceive. The target must make a Charisma saving throw. If the target’s Charisma score is equal to or lower than your own, it automatically fails this saving throw.

On a failed save, the target becomes incapable of knowingly telling a lie for the next 24 hours. The target has disadvantage deception checks if they attempt to mislead by speaking half-truths, or by omission, and creatures have advantage on Insight checks to detect such deception.

The target is aware that it has been affected by this spell and understands the nature of its effects. The spell’s effect can only be ended early by a wish spell, or divine intervention. 

At Higher Levels.

When you cast this spell using a spell slot of 8th level, the duration increases to 30 days. When you cast it using a spell slot of 9th level, the effect becomes permanent (ending only when the target dies).