Engrave your helm with the Shield Mastery rune: Increases all physical damage you deal by 10% while you have a shield equipped, and reduces the duration of all Disarm effects used against you by 50%.

Sacred Shield is a Paladin Rune introduced in Phase 2 of World of Warcraft Classic: Season of Discovery. Here's how to get your hands on it: Travel to Nijel's Point in the northern part of Desolace.