Matthew Henry Presbyterian @wholebiblehenry

Here is, 1. The escape of Abiathar, the son of Ahimelech, out of the desolations of the priests' city. Probably when his father went to appear, upon Saul's summons, he was left at home to attend the altar, by which means he escaped the first execution, and, before Doeg and his bloodhounds came to Nob, he had intelligence of the danger, and had time to shift for his own safety.

Commenting on 1 Samuel 22:20-23

John Gill Reformed Baptist @doctorgill

And Abiathar showed David that Saul had slain the Lord's priests. Of which perhaps he had not as yet heard; though tidings of such a nature generally fly swiftly; and a sorrowful shocking account he had to give, and which was so to David. And Abiathar showed David that Saul had slain the Lord's priests.

Keil & Delitzsch Lutheran @keilanddelitzsch

1Sa 22:20-23 The only one of the whole body of priests who escaped this bloody death was a son of Ahimelech, named Abiathar, who “fled after David,” i.e., to David the fugitive, and informed him of the barbarous vengeance which Saul had taken upon the priests of the Lord. Then David recognised and confessed his guilt.

Commenting on 1 Samuel 22:20-23