Mark | Gospel of Peter |
33 At noon, darkness came over the whole land until three in the afternoon. | [15] But is was midday, and darkness held fast all Judea; |
34 And at three in the afternoon Jesus cried out in a loud voice, “Eloi, Eloi, lema sabachthani?” (which means “My God, my God, why have you forsaken me?” ). | |
35 When some of those standing near heard this, they said, “Listen, he’s calling Elijah.” | and they were distressed and anxious lest the sun had set, since he was still living. For it is written for them: Let not the sun set on one put to death. |
36 Someone ran, filled a sponge with wine vinegar, put it on a staff, and offered it to Jesus to drink. | [16] And someone of them said: 'Give him to drink gall with vinegary wine.' And having made a mixture, they gave to drink. |
“Now leave him alone. Let’s see if Elijah comes to take him down,” he said. | [17] And they fulfilled all things and completed the sins on their own head. [18] But many went around with lamps, thinking that it was night, and they fell. |
[19] And the Lord screamed out, saying: 'My power, O power, you have forsaken me.' | |
37 With a loud cry, Jesus breathed his last. | And having said this, he was taken up. |
Mark has duplicated the Jesus'cry, so that it has two meanings:
1) as a false invocation to Elijiah (for the people around)
2) as a true invocation to God (for the reader and Jesus)
The effect is that the people around have hoped in vain that Elijiah was coming to save Jesus.
While Jesus, who was desperate about his end, was really vindicated by God (for the implicit reference to the Psalm).
Now note what happens in the Gospel of Peter:
The people around are the people who have to realize — and realize — their biblical prophecy or prescription, not Jesus.
So here is a possible explanation:
Mark's Gospel had the Gospel of Peter as his source. He converted a true prophecy that had to be realized on Jesus by the people around in a false prophecy that had to be realized by Elijah according to the people around.