Then said Hezekiah unto Isaiah, Good is the word of the LORD which thou hast spoken. And he said, Is it not good, if peace and truth be in my days?

Then said Hezekiah unto Isaiah, Good is the word of Jehovah which thou hast spoken. He said moreover, Is it not so, if peace and truth shall be in my days?

Ezechias said to Isaias: The word of the Lord, which thou hast spoken, is good: let peace and truth be in my days.

Good is the word - The language is, according to some, that of a true spirit of resignation and humility; according to others, that of a feeling of relief and satisfaction that the evil was not to come in his day. Such a feeling would be but natural, and though not according to the standard of Christian perfectness, would imply no very great defect of character in one who lived under the old Dispensation.
Peace and truth - Rather, "peace and continuance." The evils threatened were war and the dissolution of the kingdom.

Good is the word of the Lord - He has spoken right, I have done foolishly. I submit to his judgments.
Is it not good if peace and truth be in my days? - I believe Hezekiah inquires whether there shall be peace and truth in his days. And the question seems to be rather of an interested nature. He does not appear to deplore the calamities that were coming on the land, provided peace and truth might prevail in his days.

Then said Hezekiah unto Isaiah, Good [is] the word of the LORD which thou hast (l) spoken. And he said, [Is it] not [good], if (m) peace and truth be in my days?
(l) He acknowledges Isaiah to be the true prophet of God and therefore humbles himself to his word.
(m) Seeing that God has shown me this favour to grant me quietness during my life: for he was afraid lest the enemies would have had opportunity to rejoice if the Church had decayed in his time, because he had restored religion.

Good is the word of the Lord which thou hast spoken--indicating a humble and pious resignation to the divine will. The concluding part of his reply was uttered after a pause and was probably an ejaculation to himself, expressing his thankfulness, that, though great afflictions should befall his descendants, the execution of the divine judgment was to be suspended during his own lifetime.

The first part of Hezekiah's reply, "Good is the word of Jehovah, which thou hast spoken," is an expression of submission to the will of the Lord, like Eli's answer in 1-Samuel 3:18 (cf. 1-Kings 2:38, 1-Kings 2:42);
(Note: "He calls that good in which it is right to acquiesce, as having proceeded from Him who does nothing but what is not only most just, but tempered with the greatest goodness, even when He inflicts punishment." - Clericus.)
the second part, which the repetition of ויּאמר shows to have been spoken after a pause, and which was not addressed directly to Isaiah, "Is it not so (i.e., is it not purely goodness), if there are to be peace and truth in my days (during my life)?" is a candid acknowledgment of the grace and truth of the Lord.
(Note: "He praises the moderation of the divine decree, because when God, in accordance with His justice, might have brought this calamity upon him in his own person, for His mercy's sake He was willing to spare him and to put off the evil to a future day." - Vitringa.)
הלוא is used, as is frequently the case, in the sense of a lively affirmation. Instead of אם הלוא we have in Isaiah כּי, "for there will be peace and truth," by which this clause is attached more clearly to the first declaration as a reason for it: the word of the Lord is good, for the Lord proves His goodness and truth in the fact, that He will not inflict the merited punishment in my lifetime. "Peace and truth" are connected as in Jeremiah 33:6. אמת does not mean continuance (Ges.), security (Knobel), but fides, faithfulness-not human faithfulness, however, which preserves peace, and observes a tacit treaty (Hitzig), but the faithfulness of God, which preserves the promised grace to the humble.

Good is, &c. - I heartily submit to this sentence, as being both just, and merciful. True penitents, when they are under divine rebukes, call them not only just, but good. Not only submit to, but accept of the punishment of their iniquity. So Hezekiah did, and by this it appeared, he was indeed humbled for the pride of his heart.