in me - literally, “to me,” or, “for me”; bestow as a gift, a heart free from taint of sin (Psa 24:4; Psa 73:1).
renew - implies that he had possessed it; the essential principle of a new nature had not been lost, but its influence interrupted (Luk 22:32); for Psa 51:11 shows that he had not lost God’s presence and Spirit (1Sa 16:13), though he had lost the “joy of his salvation” (Psa 51:12), for whose return he prays.
right spirit - literally, “constant,” “firm,” not yielding to temptation.