Why God Appeared to Moses in the Flame of the Thorn Bush

Another interpretation (of Exodus 3:1): "And he drove the flock to the far side of the wilderness." Rabbi Joshua ben Korcha said: He foretold to him that his flock would perish in the wilderness, and that he would be gathered in together with it. "And he drove the flock" — He hinted to him that he would lead Israel forty years, and afterward he would be gathered in. So too Moses, when he demanded the needs of Israel: when the Holy One, blessed be He, said to him, "Go on My errand," Moses said to Him, "Tell me, you whom my soul loves, where do you graze, etc." (Song of Songs 1:7) — How many living ones are among them? How many pregnant ones are among them? How many remedies have you prepared for the pregnant ones who are among them? "Tell me, you whom my soul loves." The Holy One, blessed be He, answered him and said to him, "If you do not know, O fairest among women, go forth in the tracks of the flock, etc." (Song of Songs 1:8). Therefore, "and he drove the flock to the far side of the wilderness." When he reached Horeb, immediately what is written? "And the angel of the LORD appeared to him in a flame of fire" (Exodus 3:2). Why "in a flame of fire"? In order to win his heart, so that when he would come to Sinai and see that fire he would be in awe; therefore, "in a flame of fire." Another interpretation: Why "in a flame of fire"? A flame is placed from two parts. Why from within the thorn bush and not from within another tree? The Holy One, blessed be He, said, "I am with him in distress" (Psalms 91:15) — and they were placed in servitude, and shall I reveal Myself from within another tree? Therefore, from within the thorn bush, which is entirely of thorns.