Murmuring is an expression of the flesh, the totality of man’s fallen being (cf. Phil. 2:14). Although the thirst of the people had been quenched by the twelve springs at Elim (Exo. 15:27), the people were still hungry because of the lack of food. In such a situation the flesh of God’s people was exposed. This shows that the shortage of Christ as our spiritual nourishment will always cause our flesh with its lusts to be exposed. After the flesh was exposed, God sent manna to nourish His people (vv. 13-15). God’s way of dealing with the flesh of His people is to change their diet. The only way to conquer the flesh is to be filled with Christ by enjoying Him daily as the heavenly life supply, signified by manna (see note Exo. 16:41 and note Exo. 16:151).