They kept blessing God and singing his praises and “they began to sing hymns of praise” (Good News Translation) are two legitimate ways to express the force of the Greek verb forms used here. The difference is whether these actions are thought of as an activity to last as long as Tobit and Tobias lived (kept …) or as an action that starts to happen at this point in the narrative (“began…”) Choice of the latter may be more appropriate, as in Good News Translation, since chapter 13 gives a prayer of Tobit.

Good News Translation may not be quite as helpful here in supplying the name of Raphael, which is not in the Greek. In English the simple phrase an angel of God may carry the impact of awe more appropriately, whereas including the name may make Raphael appear simply as a friend.

An alternative translation model for this verse is:

• They began singing praises to God because of the great things [or, marvelous deeds] he had done, when one of his angels had appeared to them.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on Tobit. (UBS Helps for Translators). New York: UBS, 2001. For this and other handbooks for translators see here.