These two then, that hardship was testing discipline for Israel, and that it was also intended to be the means of revealing spirit as the supreme force even in the material world, are the main lessons of the eighth chapter. Of these the last is by far the most important. Casting back his eye upon the past, the author of Deuteronomy teaches that the trials and the victories, the wonders and the terrors of their wilderness time were meant to humble them, to empty them of their own conceits, and to make them know beyond all doubting that God alone was their portion, and that apart from Him they had no certainty of continuance in the future and no sustainment in the present. "All the commandment which I command thee this day shall ye observe to do, _that ye may live_," is the fundamental note, and the physical needs and trials of the time are cited as an object-lesson to that effect. "He humbled thee, and suffered thee to hunger, and fed thee with manna which thou knewest not; that He might make thee to know that man doth not live by bread alone, but by everything that proceedeth out of the mouth of Yahweh doth man live." Of course the first reference of the "everything that proceedeth" is to the creative word of Yahweh. The meaning is that the sending of the manna was proof that the ordinary means of living, _i.e._ bread, could be dispensed with when Yahweh chose to make use of His creative power. Many commentators think that this exhausts the meaning of the passage, and they regard our Lord's use of these words in the Temptation as limited in the same fashion. But both here and in the New Testament more must be intended. Here we have the statement in the first verse that Israel is to keep the commandments, which certainly are a part of "all that proceeds" from the mouth of God, that they may _live_. This implies that the mere possession of material sustenance is not enough for even earthly life. Impalpable spiritual elements must be mingled with "bread" if life is not to decay. This, our chapter goes on to say, would be plain to them if they would carefully consider God's dealing with them in the wilderness, for the sending of the manna was meant to emphasise and bring home to them that very truth. It was meant, in short, to convey a double lesson--the direct one above referred to, and the more remote but deeper one which had been asserted in the first verse.