1 Samuel 22:13
And Saul said unto him, Why have ye conspired against me, thou and the son of Jesse, in that thou hast given him bread, and a sword, and hast enquired of God for him, that he should rise against me, to lie in wait, as at this day? And Saul said unto him, Why have ye conspired against me, thou and the son of Jesse, in that thou hast given him bread, and a sword, and hast enquired of God for him, that he should rise against me, to lie in wait, as at this day?
Saul directly charged Ahimelech the priest with conspiring together with David the son of Jesse against him. The alleged conspiracy consisted in Ahimelech having given David bread and a sword and having inquired of God for him. Saul interpreted that assistance as enabling David to rise up against him and to lie in wait for him as on that very day.
The accusation was false, and it came after Doeg reported David's visit to Nob in terms that inflamed Saul's anger. Saul then used the charge of conspiracy to justify putting to death Ahimelech's family and the priests of Nob.