1 Samuel 22:16

‘ And the king said, “You shall surely die, Ahimelech, you, and all your father's house.”

But Saul was not listening. Ahimelech had admitted offering David help and so he and his whole house must die whether they had intended a conspiracy or not. For by their actions they had specifically injured the sacred person of the king. While this verdict might have been acceptable in a foreign court where such standards applied, it was not seemly for a king of Israel who was supposed to uphold God's Law. But that is the point that is being made here. Saul was putting himself above God's Law. He was ignoring all the claims of justice. It will also be noted that there was only one witness. In Israelite law that was insufficient to bring a conviction (Deuteronomy 19:15). It may be that Saul would have claimed that Ahimelech was himself the second witness, but in that case it would not have applied to the other priests. And in any case a man could not be convicted on what was not really a confession. Everything is wrong with this verdict. Saul is being shown up as totally unjust.