Shackling Smite

3rd-Level Evocation
Casting Time: 1 bonus action
Range: Self
Components: V
Duration: (C) 1 minute

The next time you hit a creature with a weapon attack during this spell’s duration, your weapon emits a blast of cold air and the attack deals an extra 4d8 cold damage to the target. Additionally, the target must succeed on a Strength saving throw or be Chilled until the spell ends. While a creature is chilled in this way, they are Restrained. This spell only requires concentration while a creature is Restrained by the spell, but the spell ends early if you cast it again or cast another smite spell, such as branding smite or lightning arrow.
A creature Chilled by this spell makes another Strength saving throw at the end of each of its turns. On a successful save, it is no longer Chilled.
At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the extra damage increases by 1d8 for each slot level above 3rd.

Source: Knuckleheads & Other Such Curiosities: A Travelers’ Guide to Icewind Dale