'Thank offerings' in the Bible

And Hezekiah answered, and said, "Now that ye have filled your hands to the LORD, go to and bring in the sacrifices and thank offerings into the house of the LORD." And the congregation brought in the sacrifices and thank offerings, and all that were willing brought burnt offerings.

And he made an altar unto the LORD and sacrificed thereon peace offerings and thank offerings, and charged Judah to serve the LORD God of Israel.

And though ye offer me burnt offerings and meat offerings, yet have I no pleasure therein. As for your fat thank offerings, I will not look upon them.