Jethro had no reason to be dissatisfied with the services rendered to him by his son-in-law. During the forty years Moses acted as his shepherd not one sheep was attacked by wild beasts, and the herds multiplied to an incredible degree.[111] Once he drove the sheep about in the desert for forty days, without finding a pasturing place for them. Nevertheless he did not lose a single sheep. Moses' longing for the desert was irresistible. His prophetic spirit caused him to foresee that his own greatness and the greatness of Israel would manifest themselves there. In the desert God's wonders would appear, though it would be at the same time the grave of the human herd to be entrusted to him in the future, and also his own last resting- place. Thus he had a presentiment at the very beginning of his career that the desert would be the scene of his activity, which not only came true in the present order of things, but also will be true in the latter days, when he will appear in the desert again, to lead into the promised land the generation, arisen from their graves, that he brought forth from Egyptian bondage.[112] Wandering through the desert, he reached Mount Horeb, which is called by six names, each conveying one of its distinctions. It is "the mountain of God," wherein the Lord revealed His law; "Basban," for God "came there"; "a mountain of humps," for the Lord declared all the other mountains unfit for the revelation, as "crookbackt" animals are declared unfit for sacrifices; "mountain of abode," because it is the mountain that God desired for His "abode"; Sinai, because the "hatred" of God against the heathen began at the time when Israel received the law thereon; and Horeb, "sword," because there the sword of the law was drawn upon the sinners.[113] THE BURNING THORN-BUSH When Moses drew near to Mount Horeb, he was aware at once that it was a holy place, for he noticed that passing birds did not alight upon it. At his approach the mountain began to move, as though to go forward and meet him, and it settled back into quietude only when his foot rested upon it.[114] The first thing Moses noticed was the wonderful burning bush, the upper part of which was a blazing flame, neither consuming the bush, nor preventing it from bearing blossoms as it burnt, for the celestial fire has three peculiar qualities: it produces blossoms, it does not consume the object around which it plays, and it is black of color. The fire that Moses saw in the bush was the appearance of the angel Michael, who had descended as the forerunner of the Shekinah herself to come down presently. It was the wish of God to hold converse with Moses, who, however, was not inclined to permit any interruption of the work under his charge. Therefore God startled him with the wonderful phenomenon of the burning thorn-bush. That brought Moses to a stop, and then God spoke with him.