John Calvin on Numbers 16:4

4. And when Moses heard it, he fell upon his face. There is no doubt but that he had recourse to prayer in his perplexity, since he knew that the remedy for so great an evil was only in the hand of God. It is in this respect that the magnanimity of the ungodly differs from the firmness of believers; for it often happens that unbelievers also labor in the defense of a good cause, voluntarily expose themselves to the hatred of many, undergo severe contests, and encounter of their own accord great perils; but with them obstinacy stands in the place of virtue. But those who look to God, since they know that the prosperous or unhappy events of all things are in His power, thus rely upon His providence; and when any adversity occurs, implore His faithfulness and assistance. When, therefore, Moses cast himself upon the earth, this “Telle humilite a prier;” such humility in prayer. — Fr. supplication was of more: value than all those heroic virtues in which unbelievers have ever seemed to excel.