Jael's Dagger

Weapon (dagger), very rare (requires attunement)

Jael was the original rogue. In a time when combat was dominated by men who boasted openly about feats of strength, she came out victorious through the use of deception and stealth. Assassinating commander Sisera while he slept, Jael effectively won the war for the Israelite people, and did so without risking any lives but her own.

You gain a +3 bonus to attack and damage rolls made with this magic weapon. When you hit a creature with this weapon during the first round of combat, if it was surprised when it rolled Initiative and has not taken a turn yet, it must make a DC 17 Constitution saving throw, taking additional 6d6 piercing damage on a failed save, or half as much on a success.

Bible5e custom item. Its specific properties supplement the standard magic item rules.