In John's Gospel, after receiving Magdalene's report, the disciples are surprised when they reach the Empty Tomb because "They still did not understand from Scripture that Jesus had to rise from the dead." Yet in the synoptic gospels we read:
From that time [the Mount of Transfiguration] on Jesus began to explain to his disciples that he must go to Jerusalem and suffer many things at the hands of the elders, the chief priests and the teachers of the law, and that he must be killed and on the third day be raised to life. (Matthew 16:21, see also Luke 9:22, Mark 8:21)
One way to reconcile John's report vs. that of the Synoptics is to emphasize the words "from Scripture," so that the disciples actually did know that Jesus would be raised from the dead, but they knew this from Jesus' teaching rather than from OT prophecies. But this explanation fails to account for their surprise. It seems the author's clear intent is to tell us that they were basically unaware of any teaching, whether from Jesus or scripture, that he would rise from the dead.
Is there a way to reconcile these accounts other than by focusing on the words "from Scripture?"