'Truly' in the Bible

The men said to her, "Our life for yours, if you don't talk about this business of ours; and it shall be, when Yahweh gives us the land, that we will deal kindly and truly with you."

They said to Joshua, "Truly Yahweh has delivered into our hands all the land. Moreover, all the inhabitants of the land melt away before us."

Achan answered Joshua, and said, "I have truly sinned against Yahweh, the God of Israel, and this is what I have done.