For I have said, Mercy shall be built up for ever: thy faithfulness shalt thou establish in the very heavens.
For I have said, Mercy shall be built up for ever - as a building ever progressing to completion, in contrast to one left unfinished and falling into ruins.
Thy faithfulness shalt thou establish in the very heavens - in order to be like the heavens, eternal (cf. Psalms 89:36-37; Psalms 72:5; Psalms 119:89).