What is the meaning of "Hu Meromim Yishkon"?
Radak: This king will dwell secure, like one who dwells in tall towers. The matter is repeated in different words to strengthen it.
Malbim: Chizkiyah need not fear this consuming fire, for he dwells above; the enemy cannot approach him.
What are "Metzados"?
Radak: They are strong towers.
Why does it say "Lachmo Nitan"?
Rashi: He will not request food, for Shamayim will supply food to him.
Malbim: Even if the enemy will besiege [Yerushalayim] many days, they will not need to surrender due to lack of food or water, for Hashem will supply food and water.
What is the meaning of "Meimav Ne'emanim"?
Rashi: A source of water that does not cease. I.e. his seed will grow, and all his needs will be supplied.
Radak: This teaches that there will be satiation in Chizkiyah's days, like it says "Ashreichem Zore'ei Al Kol Mayim" (32:20).
Malbim: Refer to 33:16:3:2.