patsah

At its root this verb pictures something splitting or gaping open, and in the Hebrew Bible its object is almost always a mouth. It belongs to a family of similar-sounding Hebrew verbs that all mean tearing or breaking apart, so even when it simply means "open the mouth" it keeps a sense of opening wide.

From that single picture the writers draw several uses: a mouth gaping to swallow or take something in (the ground opening to receive Abel's blood, the earth swallowing rebels, the prophet told to open wide and eat the scroll), a mouth opened against someone in mockery or menace like a predator's jaws, and a mouth opened to make a weighty statement, whether a reckless vow or a promise paid at the temple.

Writers often choose this verb instead of the ordinary word for opening (פָּתַח) precisely for its vividness. When Elihu says Job "opens his mouth" in empty words, or Isaiah pictures a conquered enemy too cowed to open its beak, the stronger verb colors the scene.

In three verses of Psalm 144 the same verb means "rescue" or "set free," with no mouth in view. Here it stands beside the ordinary word for deliverance (נָצַל) as the psalmist asks God to snatch him free from deep waters and from the hand of enemies.

Psalm 144 is a late poem that reworks older psalms, and where its model used a common rescue verb, this poet slips in the unusual "open, split" verb instead. Many scholars think the physical picture never fully disappears: to rescue is to pry the enemy's grip open and wrench the trapped person free.