At about 20 mins 30 secs: Finn repeatedly asks the grounders who is in charge here. The leader of the grounders raises a calming hand to his people and tells them to "Stay Calm" in his native tongue, Grounder Creole (per the subtitles).
The words he speaks sounds nearly identical to the English slang phrase "Chill out."
The words he speaks sounds nearly identical to the English slang phrase "Chill out."