Calvin on Gospel Invitations

Wrote Calvin (emphasis mine):

"Christ began His sermons thus, the kingdom of God is at hand, repent and believe the gospel. First of all he declareth that the treasures of mercy are set open in Him. Secondly, He requireth acceptance. Lastly, confidence in God's promises. 'To what end,' some will ask, 'do exhortations tend?' Why are not men rather left to the conduct of the Holy Spirit? Why are they solicited by exhortations, since they can only comply with them so far as the Holy Spirit enables them? This briefly is our answer: The sinner cannot impute the hardness of his heart to any one besides himself, and oh man, who art thou that wouldst impose laws on God? If he choose to prepare us by means of exhortations to receive that very grace to obey those exhortations which are addressed to us, what hast thou to object to this conduct of the Lord, and what is there in it which thou canst justly condemn?"  ("CALVINISM AND HYPER-CALVINISM: Mr. J. E. Cracknell's Reply To Mr. Wale's LETTER ON "MINISTERIAL APPEALS TO THE UNCONVERTED."")  (see here)