'Edge' in the Bible

What do you mean, that you use this proverb concerning the land of Israel, saying, The fathers have eaten sour grapes, and the children's teeth are set on edge?

These are the measures of the altar by cubits (the cubit is a cubit and a handbreadth): the bottom shall be a cubit, and the breadth a cubit, and its border around its edge a span; and this shall be the base of the altar.