Psalms 71:19

This is the middle verse of the Shabbos afternoon prayer “Tzidkascha.” Why does this verse use “Elokim” – which typically denotes G-d’s attribute of judgment - for the Name of G-d in this verse rather than “Hashem,” which describes His mercy? The Metzudas David explains that the Name used here denotes G-d’s ability to do absolutely anything. No one can prevent Him from performing His wondrous, righteous and, yes, merciful deeds.