'Unrelenting' in the Bible

The Beloved to Her Lover: Set me like a cylinder seal over your heart, like a signet on your arm. For love is as strong as death, passion is as unrelenting as Sheol. Its flames burst forth, it is a blazing flame.

"This is what the sovereign Lord says: 'The Philistines have exacted merciless revenge, showing intense scorn in their effort to destroy Judah with unrelenting hostility.

"'You have shown unrelenting hostility and poured the people of Israel onto the blades of a sword at the time of their calamity, at the time of their final punishment.