Ps 81
10I am the LORD thy God, which brought thee out of the land of Egypt: open thy mouth wide, and I will fill it.
How do we open our mouths? In prayer and in praise. In this context, it is talking about opening it in prayer. This is because there is suppose to be a response to the opening of the mouth. The limit of it is wide. Our expectations must be high and very hign. A king once said, “Ask me… to half of my kingdom”. God is not limiting our asking to the limit of His kingdom. In a passage of the Bible, it says,
Jeremiah 333Call unto me, and I will answer thee, and show thee great and mighty things, which thou knowest not.
It called it mighty things that thou knowest not. The opening of the mouth must be beyond our knowledge. Something impossible.