'Staff' in the Bible

Moreover, He said to me, “Son of man, behold, I am going to break the staff of bread in Jerusalem, and they will eat bread by weight and with anxiety, and drink water by measure and in horror,

When I send against them the deadly arrows of famine which were for the destruction of those whom I will send to destroy you, then I will also intensify the famine upon you and break the staff of bread.

“Then all the inhabitants of Egypt will know that I am the Lord,Because they have been only a staff made of reed to the house of Israel.