Ner was the father of Abner and a member of Saul’s family. He was Saul’s grandfather and Abner’s father, making Abner Saul’s uncle.
Historical Bible Dictionaries
Easton's Bible Dictionary
Light, the father of Kish (1 Chr. 8:33). 1 Sam. 14:51 should be read, “Kish, the father of Saul, and Ner, the father of Abner, were the sons of Abiel.” And hence this Kish and Ner were brothers, and Saul and Abner were first cousins (comp. 1 Chr. 9:36).
Smith's Bible Dictionary
(a light or lamp), son of Jehiel, according to (1 Chronicles 8:33) father of Abner, and grandfather of King Saul. (B.C. 1140.) Abner was, therefore, uncle to Saul, as is expressly stated in (1 Samuel 14:50)
International Standard Bible Encyclopedia (ISBE)
<p>ner (ner, "lamp"): Father of Abner (1Sa 14:50 f; 26:5,14, etc.); grandfather of Saul (1Ch 8:33). Other references, though adding no further information are 2Sa 2:8,12; 3:23,25; 28; 37; 1Ki 2:5,32, etc.</p>