46 Then He said to them, “Thus it is written, and thus it was necessary for the Christ to suffer and to rise from the dead the third day, 47 and that repentance and remission of sins should be preached in His name to all nations, beginning at Jerusalem. 48 And you are witnesses of these things. 49 Behold, I send the Promise of My Father upon you; but tarry in the city of Jerusalem until you are endued with power from on high.”
I think that about sums it up. And did Jesus say "Grace", no He did not because His very Finished Work of His death and resurrection is the Grace Paul writes in detail about. The ACT of shedding Blood, His death and His resurrection speak loud words from the pages of the OT. These were words on the day of Pentecost the Jews there knew. They knew the Suffering Servant of Isaiah 53; they understood there is no forgiveness of sins without the shedding of blood. They knew the Psalms of David which spoke of Messiah and resurrection; They knew then what Jesus meant by His reference to Jonah when explaining His resurrection. They knew all this from Peter's sermon, he gave the Jews what they knew, their very own Holy Scriptures. The Son of God the Messiah is there on every page screaming out to them and Peter guided them on target like a lazer on target.
I dare not argue with the very Author of Salvation. He is the sheperd we are the sheep. The sheep hear His Voice and follow Him.