Then Moses and Aaron went from the presence of the assembly
to the door of the tent of meeting, and fell on their faces. Numbers 20:1-6

Read Numbers 20: 1-13 for the full background to this verse. This passage (The Waters of Meribah) is from the account where the Jewish people (“the assembly”) rise up against Moses (and the LORD) for leading them into the desert with no water to drink. There was a big problem, about 700,000 people were thirsty, with no water in sight.  So Moses and his brother Aaron go off to pray, and how do they pray? They pray not standing with their hands folded or hands raised up, or even on their knees. They humbled themselves before The LORD, by praying with their faces to the ground.

This is not just a 3,500 year old story, from some old history book.  This is an example for all people, of all time periods, on how to pray to the LORD.  Do we need to pray like this every time we pray? No, but we need to understand that there are some times in our lives when falling prostrate is beneficial, and even necessary for our prayer.