Midrasch zu Jehoschua 6:5

Rabbi Chanina ben Dosa said: From that ram, which was created at the twilight, nothing came forth which was useless. The ashes of the ram were the base which was upon the top of the inner altar. The sinews of the ram were the strings of the harp whereon David played. The ram's skin was the girdle (around) the loins of Elijah, may he be remembered for good, as it is said, "And they answered him, He was an hairy man, and girt with a girdle of leather about his loins" (2 Kings 1:8). The horn of the ram of the left side (was the one) wherein He blew upon Mount Sinai, as it is said, "And it shall come to pass, that when the ram's horn soundeth long" (Josh. 6:5). (The horn) of the right side, which is larger than that of the left, is destined in the future to be sounded in the world that is to come, as it is said, "And it shall come to pass in that day, that a great trumpet shall be blown" (Isa. 27:13); and it is said, "And the Lord shall be king over all the earth" (Zech. 14:9).