What does Matthew 27:43 mean?

In English, the expression "putting on a clinic" means to demonstrate something in a definitive way. The religious leaders who condemned Jesus to death are "putting on a clinic" in cruel mockery. As a mutilated (John 19:1–4), crucified man (Matthew 27:35–38) hangs in agony, they join in viciously insulting and making fun of Him (Matthew 27:39–42). Now they add one more hurtful insult to the list. They joke that if God really wants Jesus, who trusts in Him, then God should save Him now. After all, Jesus claimed to be God's Son.

At this point, the religious leaders are not speaking to Him, they are laughing with each other about Him within His hearing. To them, His dying on the cross is evidence He was never the Messiah He claimed to be. The fact that He can be killed in this way means that His power must have been false. They are patting themselves on the back for convincing Pilate to crucify the man (Matthew 27:24).

We're not told Jesus' emotional reaction to any of these insults. One can assume, though, this one would be especially hurtful. Jesus is the Son of God, and He knows that God the Father is the one ultimately responsible for His death on this cross (Matthew 26:39). God the Father is sacrificing God the Son to offer salvation to humanity (Romans 5:19). Jesus even alluded to this when Pilate claimed authority to have Jesus crucified: "You would have no authority over me at all unless it had been given you from above" (John 19:11). Isaiah, describing the will of God the Father in this moment, put it this way, "Yet it was the will of the Lord to crush him; he has put him to grief" (Isaiah 53:10).

Jesus is dying on the cross by His own choice and in submission to the will of God the Father. In some impossible to understand way, there is at least a feeling of separation between Him and the Father, as He is being crushed, which would have been devastating. Jesus will soon cry out, "My God, my God, why have you forsaken me?" (Matthew 27:46).