How does a suspension delay harmonic resolution?

A suspension delays harmonic resolution by prolonging a note from a previous chord while the other voices shift to a new, underlying harmony.12

Because the sustained note does not belong to the new chord, it creates a momentary dissonance against the other voices. This tension persists until the suspended note moves by a stepwise motion to a pitch that is consonant with the new chord. By holding back the expected consonant harmony, the suspension builds anticipation and enhances the sense of arrival or completeness when it finally resolves, a technique frequently used by composers to provide expressive weight to cadences.21