1 Samuel 25:14-16

But one of the young men told Abigail, Nabal's wife, saying, Behold, David sent messengers out of the wilderness to salute our master; and he railed on them. But the men were very good unto us, and we were not hurt, neither missed we any thing, as long as we were conversant with them, when we were in the fields: they were a wall unto us both by night and day, all the while we were with them keeping the sheep.