Hazael King Over Syria, Ahaziah King Over Judah, and Jehu Anointed King Over Israel
Why did Elisha go to Syria? Ben-Hadad II, king of Syria, felt that his arrival was accidental. But, in fact, Elisha was fulfilling a commission that had earlier been given to Elijah. At Mount Sinai, God had commissioned Elijah to anoint Hazael king over Syria, Jehu king over Judah and Elisha as a prophet in his place (1 Kings 19:15-16 1 Kings 19:15-16  And the LORD said to him, Go, return on your way to the wilderness of Damascus: and when you come, anoint Hazael to be king over Syria:
 And Jehu the son of Nimshi shall you anoint to be king over Israel: and Elisha the son of Shaphat of Abelmeholah shall you anoint to be prophet in your room.
American King James Version×). Yet Elijah did not finish this commission. He anointed Elisha but not Hazael or Jehu. Thus, Elisha is now being used to complete Elijah's commission, appearing here on the scene at the time of the prophesied transfer of power.
When Ben-Hadad, who had fallen sick, heard that Elisha had come to Damascus, he asked his assistant Hazael to inquire of him whether he, the king, would recover. Elisha notified the king that he would recover, but he went on to explain that he knew that the king would die (2 Kings 8:7-10 2 Kings 8:7-10  And Elisha came to Damascus; and Benhadad the king of Syria was sick; and it was told him, saying, The man of God is come here.
 And the king said to Hazael, Take a present in your hand, and go, meet the man of God, and inquire of the LORD by him, saying, Shall I recover of this disease?
 So Hazael went to meet him, and took a present with him, even of every good thing of Damascus, forty camels' burden, and came and stood before him, and said, Your son Benhadad king of Syria has sent me to you, saying, Shall I recover of this disease?
 And Elisha said to him, Go, say to him, You may certainly recover: however, the LORD has showed me that he shall surely die.
American King James Version×). Though seemingly inconsistent, this was nonetheless a truthful statement considering that the king would not die because of his sickness, but because he would be murdered by Hazael. Elisha also told Hazael that he would be the next king of Syria, and that the war he would wage against Israel would be severe and brutal (verses 12-15). Elisha must have anointed Hazael at this time, between verses 13 and 14.
After Jehoram, king of Judah, died, Ahaziah, his youngest son, became his successor. He was only 22 years old and reigned only one year. He was a wicked king, the "son-in-law of the house of Ahab" (2 Kings 8:27 2 Kings 8:27And he walked in the way of the house of Ahab, and did evil in the sight of the LORD, as did the house of Ahab: for he was the son in law of the house of Ahab.
American King James Version×). He followed the bad advice of his mother Athaliah and his counselors (2 Chronicles 22:1-6 2 Chronicles 22:1-6  And the inhabitants of Jerusalem made Ahaziah his youngest son king in his stead: for the band of men that came with the Arabians to the camp had slain all the oldest. So Ahaziah the son of Jehoram king of Judah reigned.  Forty and two years old was Ahaziah when he began to reign, and he reigned one year in Jerusalem. His mother's name also was Athaliah the daughter of Omri.  He also walked in the ways of the house of Ahab: for his mother was his counselor to do wickedly.  Why he did evil in the sight of the LORD like the house of Ahab: for they were his counsellors after the death of his father to his destruction.  He walked also after their counsel, and went with Jehoram the son of Ahab king of Israel to war against Hazael king of Syria at Ramothgilead: and the Syrians smote Joram.  And he returned to be healed in Jezreel because of the wounds which were given him at Ramah, when he fought with Hazael king of Syria. And Azariah the son of Jehoram king of Judah went down to see Jehoram the son of Ahab at Jezreel, because he was sick.
American King James Version×). Pursuant to their advice, he engaged in warfare together with Israel's King Joram, referred to earlier as Jehoram, against Hazael, king of Syria. The Syrians, however, wounded Joram, and Ahaziah visited him in Jezreel (2 Kings 8:25-29 2 Kings 8:25-29  In the twelfth year of Joram the son of Ahab king of Israel did Ahaziah the son of Jehoram king of Judah begin to reign.  Two and twenty years old was Ahaziah when he began to reign; and he reigned one year in Jerusalem. And his mother's name was Athaliah, the daughter of Omri king of Israel.  And he walked in the way of the house of Ahab, and did evil in the sight of the LORD, as did the house of Ahab: for he was the son in law of the house of Ahab.  And he went with Joram the son of Ahab to the war against Hazael king of Syria in Ramothgilead; and the Syrians wounded Joram.  And king Joram went back to be healed in Jezreel of the wounds which the Syrians had given him at Ramah, when he fought against Hazael king of Syria. And Ahaziah the son of Jehoram king of Judah went down to see Joram the son of Ahab in Jezreel, because he was sick.
American King James Version×). It is interesting to note that this battle was fought at Ramoth Gilead (verse 28), the same place Ahab and Jehoshaphat had fought against Ben-Hadad, which resulted in the wounding and death of Ahab (1 Kings 22).
It was now time for Jehu to be anointed king of Israel. To complete Elijah's commission, Elisha sends one of the sons of the prophets to do the anointing (2 Kings 9:1-6 2 Kings 9:1-6  And Elisha the prophet called one of the children of the prophets, and said to him, Gird up your loins, and take this box of oil in your hand, and go to Ramothgilead:
 And when you come thither, look out there Jehu the son of Jehoshaphat the son of Nimshi, and go in, and make him arise up from among his brothers, and carry him to an inner chamber;
 Then take the box of oil, and pour it on his head, and say, Thus said the LORD, I have anointed you king over Israel. Then open the door, and flee, and tarry not.
 So the young man, even the young man the prophet, went to Ramothgilead.
 And when he came, behold, the captains of the host were sitting; and he said, I have an errand to you, O captain. And Jehu said, To which of all us? And he said, To you, O captain.
 And he arose, and went into the house; and he poured the oil on his head, and said to him, Thus said the LORD God of Israel, I have anointed you king over the people of the LORD, even over Israel.
American King James Version×). (As an aside, there's an interesting lesson here. God often commissions one of His servants to fulfill a task, which may span many years and include several other servants of God. That is, the commission given to one person isn't necessarily fulfilled by that person alone.) God's command to Jehu is that he "strike down the house of Ahab your master, that I may avenge the blood of my servants the prophets, and the blood of all the servants of the Lord, at the hand of Jezebel [the infamous wicked wife of Ahab]" (2 Kings 9:6-7 2 Kings 9:6-7  And he arose, and went into the house; and he poured the oil on his head, and said to him, Thus said the LORD God of Israel, I have anointed you king over the people of the LORD, even over Israel.  And you shall smite the house of Ahab your master, that I may avenge the blood of my servants the prophets, and the blood of all the servants of the LORD, at the hand of Jezebel.
American King James Version×).