They were a wall to us both by night and day, all the while we were with them feeding the sheep.

a wall they have been unto us both by night and by day, all the days of our being with them, feeding the flock.

But day and night they were like a wall round us while we were with them, looking after the sheep.

They were a wall to us, as much in the night as in the day, during all the days that we were with them, pasturing the sheep.

A wall - To protect them from the attacks of the Bedouins, etc. They had been as safe with David's men around them as if they had been dwelling in a walled town.

They were a wall unto us both by night and day,.... Protecting and defending them against the Philistines, who, as they robbed the threshing floors of Keilah, would have plundered the flocks of Nabal; or it may be rather against the incursions of the Arabs in the wilderness of Paran, the posterity of Ishmael, who lived by plunder, and against the wild beasts of the desert, who otherwise would have carried off many of their sheep and lambs, by night or by day:
all the while we were with them keeping the sheep; all which showed how reasonable it was that Nabal should have used them well, and given them a portion of his entertainment at his sheep shearing; for had it not been for them, he would not have had so many sheep to shear as he had.