John Gill Commentary 1 Samuel 14:51

"And Kish was the father of Saul; and Ner the father of Abner was the son of Abiel." — 1 Samuel 14:51 (ASV)

And Kish was the father of Saul
See (1 Samuel 9:1)

and Ner the father of Abner was the son of Abiel ;
this Abiel was the father both of Kish and Ner, and the grandfather of Saul, see (1 Samuel 9:1) .