History of Psalm 91
Please give the biblical history of Psalm 91. Who wrote it and when?
Let me say that there are several ways to tell who wrote a psalm. The easiest way is to look at the title. The title to Psalm 90, for example, is “A prayer of Moses the man of God.” Obviously Moses penned the words to that psalm. Psalm 91, however, has no title, so we are not able to identify the author that way.
If the psalm has no title to identify the writer, there is a second way to discover who that person was. If another passage of scripture quotes a portion of the psalm and ascribes it to a writer not identified by the title. For example, Psalm 2 has no title, but verses 1 and 2 are quoted in Acts 4:25-26. In verse 25 of that chapter, we are told that David wrote Psalm 2. Unfortunately, I have not found any passages that identify the writer of Psalm 91.
Many of the commentators ascribe the Psalm to Moses, and that might be right. I think they follow a Jewish tradition that says if the writer of a particular psalm is not identified in the title of that psalm then you can go back to the nearest psalm that is titled and safely assume that it is the same author. Since Psalm 90 is clearly ascribed to Moses, they would say that Psalm 91 is also a psalm of Moses. I would hesitate to endorse that wholeheartedly, but I guess Moses is as good of a guess as anyone. In verse 14 of Psalm 91, the phrase set his love upon me is found. The only other place in the Bible where that phrase (or at least something very close to that phrase) is found is in Deuteronomy 7:7 “The LORD did not set his love upon you, nor choose you, because ye were more in number than any people; for ye were the fewest of all people.” The Book of Deuteronomy is obviously one of the books that Moses wrote so that might be some evidence to support the assumption that Moses is the writer of this psalm.