The use of the verb healed in verse 20 shows that the people in this strophe are sick as a result of their sins. Yahweh’s spoken command is literally he sent forth his word. That word healed them and delivered them. He sent forth his word indicates an action, whereas Good News Translation “with his command” serves as an instrumental phrase. In many languages it will be better to recast the speaking and the healing and say, for example, “he spoke and they were healed” or “the word which he spoke healed them.” The verb delivered (Good News Translation “saved”) here is the same as the one used in 41.1b and is different from the ones used in verses 6 and 9. Destruction in line b translates a word whose form and meaning are in doubt; but most commentators take it to mean “their pits,” a synonym for Sheol. Most translations have either “the grave” or “death.” New English Bible, Bible de Jérusalem, and New Jerusalem Bible follow an emended text which means “(he saved) their lives from the abyss.” The expression delivered them from destruction (“saved them from the grave”) will have to be adjusted in some languages to say “he did not let them die” or “he kept them alive.”
Verse 21 is exactly like verse 15.
Sacrifices of thanksgiving refers to offerings which expressed the gratitude of the people. Verse 22 specifies that such sacrifices should be offered (see “Sacrifice” in 40.6), as the healed worshipers joyfully proclaim in the Temple what Yahweh has done for them. In the Masoretic text, in the margin of verses 21-26 and of verse 40, there is an inverted letter nun. There is no certain knowledge of the meaning of this. Some take it as an indication that the verses are out of place (see Kautzsch-Cowley).
Quoted with permission from Bratcher, Robert G. and Reyburn, William D. A Handbook on the Book of Psalms. (UBS Helps for Translators). New York: UBS, 1991. For this and other handbooks for translators see here .