Thou hast multiplied the nation: The pronoun Thou refers to God, so Contemporary English Version opens with “Our LORD, you….” Good News Translation and Bible en français courant also mention the Lord as the person who is being addressed. For this line Masoretic Text has literally “You have not increased the nation.” This is the ketiv (what is written in the text). The qere (what should be read in its place) in Masoretic Text is “You have increased the nation for it” (recommended by Hebrew Old Testament Text Project). Some scholars suggest that the text should be modified to read “You have increased its happiness.” This rendering keeps very close to the Hebrew text and also makes a good parallel with the next line, so we recommend accepting this change, a change that is followed by many translations. A more idiomatic way to say this is “You have given the nation so much happiness” (see Good News Translation). Bible en français courant (1997) is more conservative with “you have made the nation become great.” New International Version has “You have enlarged the nation.”

Thou hast increased its joy: If we follow the suggestion for interpreting the first line in the sense of “increased happiness,” then this second line is parallel to it. The Hebrew root rendered joy occurs two more times in this verse (as rejoice in the third line and as joy again in the fourth line).

They rejoice before thee means they rejoice or are happy about what God has done for them. Before is not a location phrase though it can mean “in your presence.” Here it may be best to render it as “because of what you have done” (similarly Good News Translation).

As with joy at the harvest, as men rejoice when they divide the spoil: Both these examples illustrate the nature of the people’s joy. In the first example their joy is compared to the celebration at harvest time. In the second one it is like the joy of soldiers returning victorious from battle, carrying home the spoil. Divide the spoil refers to sharing the war booty with all the members of the community. In some languages more detail is needed to make the expressions meaningful; for example, they may be rendered “as people rejoice when they have [safely] stored the produce of their farms, or as soldiers rejoice when they share with their people what they took in war.”

Translation examples for this verse are:

• You have given the people of the nation so much happiness,
you have added to their joy.
They are as joyous for what you have done as they are at harvest time,
or as when soldiers return with spoils from battle.

• You have made the nation so happy;
you have added to their joy.
They celebrate before you as they do at harvest time,
or when they divide things taken after a victory in battle.

Quoted with permission from Ogden, Graham S. and Sterk, Jan. A Handbook on Isaiah. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here .