This psalm is the first in a series of fifteen psalms, called from ancient times psalms of ascent, or psalms of degree. What this means is frankly lost to us, but there have been reasonable speculations. John Calvin thought it had to do with the musical pitch of the psalm. A medieval rabbi said that the temple had fifteen steps, one psalm per step. I favor the view that argues that these are pilgrim psalms. When Israelites went to Jerusalem to worship at the Temple, they were going up (Ex. 34:24; 1 Kings 12:27).