John Gill Commentary 1 Samuel 14:18

"And Saul said unto Ahijah, Bring hither the ark of God. For the ark of God was [there] at that time with the children of Israel." — 1 Samuel 14:18 (ASV)

And Saul said to Ahiah, bring here the ark of the Lord ,
&c.] That he, the high priest, might put on the ephod, with the Urim and Thummim, and inquire by them of the Lord before it, concerning the affair of Jonathan, what he had done, and the agitation that was in the host of the Philistines; so the Septuagint version, "bring the ephod", of which, with the Urim and Thummim, Kimchi interprets it; and ask, whether it was right for him to go out to them, or continue where he was:

for the ark of God was at that time with the children of Israel ;
and so it always was, except a few months it was in the hands of the Philistines; so it was at Kirjathjearim, where it was last. Jarchi thinks a word is wanting, and to be supplied thus, "the ark of God was [there] at that time with the children of Israel," at Gibeah; perhaps it might be removed first to Gilgal, when Saul and Samuel were there, and when they came to Gibeah it was brought along with them; but the last words may be considered as a distinct clause, and, literally rendered, are, "and the children of Israel": which Abarbinel accounts for thus, and Saul said this,

bring here the ark of the Lord ;
and the children of Israel said so likewise, joined with him in it: though the ark had been with Saul, and the people, some time, and also the high priest, yet we do not find that Saul in all his straits and difficulties consulted the Lord before; but perceiving something extraordinary was doing, and might turn to his advantage, he begins to inquire.