'Unless' in the Bible

And the men of the city say to him on the seventh day, before the sun goeth in: -- 'What is sweeter than honey? And what stronger than a lion?' And he saith to them: 'Unless ye had ploughed with my heifer, Ye had not found out my riddle.'

Samson said to them, "If you want to behave like this, [I swear] I will not rest unless I have taken revenge on you."