John Gill

Yea, they shall sing in the ways of the Lord,.... Which are all mercy and truth; ways of pleasantness, and paths of peace: so the eunuch went on his way, and in the ways of the Lord rejoicing, Act 8:39; Or, "they shall sing of the ways of the Lord" (t); of the excellency, pleasure, and usefulness of them; for great is the glory of the Lord; shown in the works of creation; more especially in the person of Christ, and in the glorious work of redemption and salvation by him; and of which there will be a great display throughout the earth in the latter day, by means of the Gospel, the great spread of it, and the multitude of persons converted by it; which will make the ways of the Lord still more pleasant; see Isa 6:3. (t) "de viis Jehovae", Piscator, Schmidt; so some in Vatablus.