The song from which the title is derived, "NoHidingPlace," refers to the Book of Revelation, in which man attempts to hide from the wrath of God in mountains and rocks.
No, as a rule, Harlan doesn't suggest titles; "Rock" came from the quote from the Bible, which was later made into a gospel song, used in the show.
Second, as I seem to recall, the line about "nohidingplace" is taken from the Old Testament, which forms a substantial portion of Judaic teachings (but not the whole of it, a mistake many make).