Question: In Matthew it’s reported that Jewish authorities tried to cover up the resurrection of Jesus by saying the disciples stole the body while the guards were sleeping. I don’t buy it. How would Matthew know about this story, since it was a secret conversation the authorities had with the guards? And how could they ask the guards to claim they’d fallen asleep since such a crime would have been punishable by death? The story just doesn’t fly.
Answer: Here’s the account your referring to.
Matt. 28:12-15: When the chief priests had met with the elders and devised a plan, they gave the soldiers a large sum of money, telling them, “You are to say, ‘His disciples came during the night and stole him away while we were asleep.’ If this report gets to the governor, we will satisfy him and keep you out of trouble.” So the soldiers took the money and did as they were instructed. And this story has been widely circulated among the Jews to this very day.
It seems to me the text answers your question. Matthew could have easily known about the story since it was “widely circulated.” (Or he could have known about it by divine inspiration, if that was required). The guards ordinarily would have gotten in deep trouble for sleeping on the job, except that in this case the Jewish authorities promised to use their influence to “keep [them] out of trouble.” What the Jewish authorities didn’t want was the guards going around telling people what they actually saw!
What’s most interesting, I think, is that this lie is premised on the assumption that the tomb was in fact empty. What this tells us is that when Matthew wrote his Gospel (usually dated 70 to 80 A.D., but I would argue for a pre-70 A.D. date), those who were hostile to Christianity (and there were many) didn’t deny there was any empty tomb. They just offered a counter explanation as to how it became empty. If you don’t believe their counter-explanation, you have to come up with your own. And the best one available, I submit, is the one the disciples themselves offer: Jesus actually rose from the dead.