A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
4 Kings (2 Kings) 5:1
kg2 5:1NAAMAN'S LEPROSY. (Kg2 5:1-7)
Naaman, captain of the host of the king of Syria, was a great man with his master--highly esteemed for his military character and success.
and honourable--rather, "very rich."
but he was a leper--This leprosy, which, in Israel, would have excluded him from society, did not affect his free intercourse in the court of Syria.
4 Kings (2 Kings) 5:2
kg2 5:2a little maid--who had been captured in one of the many predatory incursions which were then made by the Syrians on the northern border of Israel (see Sa1 30:8; Kg2 13:21; Kg2 24:2). By this young Hebrew slave of his wife, Naaman's attention was directed to the prophet of Israel, as the person who would remove his leprosy. Naaman, on communicating the matter to his royal master, was immediately furnished with a letter to the king of Israel, and set out for Samaria, carrying with him, as an indispensable preliminary in the East, very costly presents.
4 Kings (2 Kings) 5:5
kg2 5:5ten talents of silver--Â£3421; 6000 shekels of gold; a large sum of uncertain value.
ten changes of raiment--splendid dresses, for festive occasions--the honor being thought to consist not only in the beauty and fineness of the material, but on having a variety to put on one after another, in the same night.
4 Kings (2 Kings) 5:7
kg2 5:7when the king of Israel had read the letter, that he rent his clothes--According to an ancient practice among the Eastern people, the main object only was stated in the letter that was carried by the party concerned, while other circumstances were left to be explained at the interview. This explains Jehoram's burst of emotion--not horror at supposed blasphemy, but alarm and suspicion that this was merely made an occasion for a quarrel. Such a prince as he was would not readily think of Elisha, or, perhaps, have heard of his miraculous deeds.
4 Kings (2 Kings) 5:8
kg2 5:8ELISHA SENDS HIM TO JORDAN, AND HE IS HEALED. (Kg2 5:8-15)
when Elisha the man of God had heard that the king of Israel had rent his clothes, that he sent to the king, saying, . . . let him come now to me--This was the grand and ultimate object to which, in the providence of God, the journey of Naaman was subservient. When the Syrian general, with his imposing retinue, arrived at the prophet's house, Elisha sent him a message to "go and wash in Jordan seven times." This apparently rude reception to a foreigner of so high dignity incensed Naaman to such a degree that he resolved to depart, scornfully boasting that the rivers of Damascus were better than all the waters of Israel.
4 Kings (2 Kings) 5:11
kg2 5:11strike his hand over the place--that is, wave it over the diseased parts of his body. It was anciently, and still continues to be, a very prevalent superstition in the East that the hand of a king, or person of great reputed sanctity, touching, or waved over a sore, will heal it.
4 Kings (2 Kings) 5:12
kg2 5:12Abana and Pharpar--the Barrady and one of its five tributaries--uncertain which. The waters of Damascus are still highly extolled by their inhabitants for their purity and coldness.
4 Kings (2 Kings) 5:14
kg2 5:14Then went he down, and dipped himself seven times in Jordan--Persuaded by his calmer and more reflecting attendants to try a method so simple and easy, he followed their instructions, and was cured. The cure was performed on the basis of God's covenant with Israel, by which the land, and all pertaining to it, was blessed. Seven was the symbol of the covenant [KEIL].
4 Kings (2 Kings) 5:15
kg2 5:15ELISHA REFUSES NAAMAN'S GIFTS. (Kg2 5:15-19)
he returned to the man of God--After the miraculous cure, Naaman returned to Elisha, to whom he acknowledged his full belief in the sole supremacy of the God of Israel and offered him a liberal reward. But to show that he was not actuated by the mercenary motives of the heathen priests and prophets, Elisha, though he accepted presents on other occasions (Kg2 4:42), respectfully but firmly declined them on this, being desirous that the Syrians should see the piety of God's servants, and their superiority to all worldly and selfish motives in promoting the honor of God and the interests of true religion.
4 Kings (2 Kings) 5:17
kg2 5:17two mules' burden of earth--with which to make an altar (Exo 20:24) to the God of Israel. What his motive or his purpose was in this proposal--whether he thought that God could be acceptably worshipped only on his own soil; or whether he wished, when far away from the Jordan, to have the earth of Palestine to rub himself with, which the Orientals use as a substitute for water; or whether, by making such a request of Elisha, he thought the prophet's grant of it would impart some virtue; or whether, like the modern Jews and Mohammedans, he resolved to have a portion of this holy earth for his nightly pillow--it is not easy to say. It is not strange to find such notions in so newly a converted heathen.
4 Kings (2 Kings) 5:18
kg2 5:18goeth into the house of Rimmon--a Syrian deity; probably the sun, or the planetary system, of which a pomegranate (Hebrew, Rimmon) was the symbol.
leaneth on my hand--that is, meaning the service which Naaman rendered as the attendant of his sovereign. Elisha's prophetic commission not extending to any but the conversion of Israel from idolatry, he makes no remark, either approving or disapproving, on the declared course of Naaman, but simply gives the parting benediction (Kg2 5:19).
4 Kings (2 Kings) 5:20
kg2 5:20GEHAZI, BY A LIE, OBTAINS A PRESENT, BUT IS SMITTEN WITH LEPROSY. (Kg2 5:20-27)
I will run after him, and take somewhat of him--The respectful courtesy to Elisha, shown in the person of his servant, and the open-handed liberality of his gifts, attest the fulness of Naaman's gratitude; while the lie--the artful management is dismissing the bearers of the treasure, and the deceitful appearance before his master, as if he had not left the house--give a most unfavorable impression of Gehazi's character.
4 Kings (2 Kings) 5:23
kg2 5:23in two bags--People in the East, when travelling, have their money, in certain sums, put up in bags.
4 Kings (2 Kings) 5:27
kg2 5:27leper as white as snow--(See on Lev 13:3). This heavy infliction was not too severe for the crime of Gehazi. For it was not the covetousness alone that was punished; but, at the same time, it was the ill use made of the prophet's name to gain an object prompted by a mean covetousness, and the attempt to conceal it by lying [KEIL].