Psalms 109:4 - Ellicott's Commentary On The Whole Bible

For my love... — i.e., in return for my love I give myself unto prayer. For a concise expression of the same kind as “I prayer,” see Psalms 120:7, “I peace.” Of course the psalmist means, that in the face of all the taunts and reproaches of his maligners, he simply and naturally has recourse to prayer, and, as the context seems to indicate, prayer for them.