Shield of Faith

Cleric    Paladin

Level 1 Abjuration

Casting Time: 1 bonus action
Range: 60 feet
Components: V, S, M (a small parchment with a bit of holy text written on it)
Duration: Concentration, up to 10 minutes

A shimmering field appears and surrounds a creature of your choice within range, granting it a +2 bonus to AC for the duration.

Source: Player's Handbook, p. 275