1 Samuel 22:22

And David said unto Abiathar, I knew it that day, when Doeg the Edomite was there, that he would surely tell Saul: I have occasioned the death of all the persons of thy father’s house.

Cross-reference

1 Samuel 21:1-9 recounts David's visit to Nob where Doeg was present — the event David blames himself for here.

1 Samuel 21:2 records David's lie to Ahimelech — the deception that enabled Doeg's report and led to the massacre David laments here.

1 Samuel 27:11 shows David later killing to prevent reports — a contrast to his remorse here over the deaths he caused indirectly.