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.

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

25:12-17 God is kind to the evil and unthankful, and why may not we be so? David determined to destroy Nabal, and all that belonged to him. Is this thy voice, O David? Has he been so long in the school of affliction, where he should have learned patience, and yet is so passionate? He at other times was calm and considerate, but is put into such a heat by a few hard words, that he seeks to destroy a whole family. What are the best of men, when God leaves them to themselves, that they may know what is in their hearts? What need to pray, Lord, lead us not into temptation!