Psalms move between lament and praise, so they are read as honest emotion offered upward. A psalm in a dream reflects grief, gratitude or both at once, looking for a place to go.
Has this come up in your dreams before? What was going on in your life then?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.