'Burden' in the Bible

And Naaman said, If not, then let there, I pray thee, be given to thy servant two mules' burden of this earth; for thy servant will no more offer burnt-offering and sacrifice to other gods, but to Jehovah.

And Hazael went to meet him, and took with him a present, even of every good thing of Damascus, forty camels' burden; and he came and stood before him, and said, Thy son Ben-Hadad king of Syria has sent me to thee, saying, Shall I recover from this disease?

And he said to Bidkar his captain, Take him up and cast him in the plot of the field of Naboth the Jizreelite. For remember how, when I and thou rode together after Ahab his father, that Jehovah laid this burden upon him: