In | Workbook: Historical Notes in the Psalms, Part 3

Each note references a situation in which David’s life was in danger. Because the other three hymns labeled as “miktams” (16, 58 and 59) also reference threats to David’s life, some have suggested that this word miktam is a reference to a “silent hymn,” or a “silent prayer.” This is meant to indicate times when David could not have sung or spoken out loud. Each miktam describes David in a situation where stealth or secrecy may have been important for his survival.

Reference: C. Hassell Bullock, Encountering the Book of Psalms, 001, pp. 27-30.