In fact, the fold was a solid and enduring building, made of stone. Thus in Numbers xxxii. it is related that the tribes of Reuben and Gad, who had great quantities of Sheep and other cattle, asked for the eastward side of Jordan as a pasture-ground, promising to go and fight for the people, but previously to build fortified cities for their families, and folds for their cattle, the folds being evidently, like the cities, buildings of an enduring nature. In some places the folds are simply rock caverns, partly natural and partly artificial, often enlarged by a stone wall built outside it. It was the absence of these rock caverns on the east side of Jordan that compelled the Reubenites and Gadites to build folds for themselves, whereas on the opposite side places of refuge were comparatively abundant. See, for example, the well-known history related in 1 Sam. xxiii.-xxiv. David and his miscellaneous band of warriors, some six hundred in number, were driven out of the cities by the fear of Saul, and were obliged to pass their time in the wilderness, living in the "strong holds" (xxiii. 14, 19), which we find immediately afterwards to be rock caves (ver. 25). These caves were of large extent, being able to shelter these six hundred warriors, and, on one memorable occasion, to conceal them so completely as they stood along the sides, that Saul, who had just come out of the open air, was not able to discern them in the dim light, and David even managed to approach him unseen, and cut off a portion of his outer robe. That this particular cave was a sheepfold we learn from xxiv. 2-4: "Then Saul took three thousand chosen men out of all Israel, and went to seek David and his men upon the rocks of the wild goats. And he came to the sheepcotes by the way." Into these strongholds the Sheep are driven towards nightfall, and, as the flocks converge towards their resting-place, the bleatings of the sheep are almost deafening. The shepherds as well as their flocks found shelter in these caves, making them their resting-places while they were living the strange, wild, pastoral life among the hills; and at the present day many of the smaller caves and "holes of the rock" exhibit the vestiges of human habitation in the shape of straw, hay, and other dried herbage, which has been used for beds, just as we now find the rude couches of the coast-guard men in the cliff caves of our shores.