I know so much of these stories of Elijah in a garbled form from my childhood Sunday School lessons. Jezebel threatened Elijah. Despite having just put the 450 priests of Baal to death - and perhaps in the adrenalin let down following this - Elijah decided fighting Ahab and Jezebel was too difficult. Perhaps he thought that if they wouldn't submit to God after three years plus of drought and a mighty display of God's power, there was no point in trying any longer. As a prophet, up to this point he had failed despite God's miracles, to turn Ahab and Jezebel from their pagan practices to God. He was in despair (v4), " 'I have had enough LORD', he said. 'Take my life...' "
Yet twice God sent an angel to feed Elijah and fortify him for his jhourney to Horeb. Strengthened and enervated, he travelled the religiously significant 40 days and 40 nights into the desert to the mountain of God.
~40 days and nights of rain began the flood (Genesis 7)
~Joseph's body was embalmed over 40 days and nights (Genesis 50:3)
~12 men explored the Promised Land for 40 days and nights before reporting back to Moses (Numbers 13:25)
~Goliath the Philistine challenged Saul and Israel for 40 days before David took up the challenge and killed him (1 Samuel 17:16)
When Elijah was at Horeb, the word of the LORD came to him and the LORD spoke to him and called him to stand in His presence as He passed by and a voice spoke again " 'What are you doing here, Elijah?' " (v13, cf v9). God told him to " 'go back the way you came..' " (v15) to annoint 3 men: a new king of Aram, a new king of Israel and a new prophet to succeed Elijah. It can't have been too comforting being told to annoint his own replacement, considering his thoughts of death 40 days before. But Elijah would have been comforted, I think, by the idea that God would use these men to enact His judgement and also that a faithful rmenant would remain in Israel.