“Come. And let him that heareth say, “ Come” and let him that is athirst come. And whosoever will, let him take of the water of life freely.”In this series of sermons on the given text, Greenhill is careful to explain who Christ is as the root and offspring of David, and who it is that may come to him and drink. Greenhill says:
“ Objection, but surely these invitations are in vain if a man cannot come when he is invited. To what end are they? Answer: The sun shines upon the rock, and the rain falls upon the rock, yet no man expects that the sun should melt the rocks or the rain should make the rocks fruitful. But the adjacent parts and fields have the benefit; and so, though invitations fall upon rocks, yet other persons may have the benefit.”The rocks will not receive the benefit, but the field shall.
– McMahon, C. Matthew in The Two Wills of God