Moses and Elijah had each been forty days on Mount Horeb. Moses stood there without fear, (the only one who had ever done so), and when the glory passed, his face shone. He did not know it, but the people saw it and were afraid, so that Moses had to put on a veil. Moses there heard God's voice in answer to his pleading for the people.
Elijah, on the other hand, remained in his cave, fearing to obey the word to "go forth," all the while that God was making His power known, and when the "still small voice" was heard. Elijah was too far off to catch what the voice said. Unlike Moses, he pleads against the people, but God answers. "I have reserved 7.000 men," etc. Elijah could not stand with God in the storm, nor was he allowed to go on with his testimony. He was taken away and Elisha succeeded him.
On the mount of transfiguration, however, both he and Moses are seen talking with Jesus. There is no word of reproof, no mark of distinction. God called Elijah out of the cave, but he never got beyond the entrance, even when the still, small voice aroused him. Moses on the contrary went boldly up to the very "top of the rock." where there was no shelter, and God put him in a cleft of the rock and covered him with His hand, when the glory passed, and he was near enough to hear the wondrous words proclaimed.
Still it is blessed and comforting to find how the failure of even the best of men serves to set grace in relief. Elijah got discouraged after his most remarkable testimony, and requested for himself that Ile might die, but God took him up by a whirlwind into heaven (1 Kings 19:4; 2 Kings 2:1-11), seemingly to reserve him for the transfiguration scene. where he was to appear with Moses.