“the stalks of flax that she had spread out on the roof.” Flax was cut, dried, and eventually pounded into fibers which were then woven into clothes, oil lamp wicks, etc. The flax stalks were cut and then laid out in the sun to dry, usually for a few weeks, but less if the air was dry and the sun was hot, and a perfect place to do that was on top of a flat roof where the sun would dry them quickly. The fact that Rahab could hide men under the flax on the roof showed that Rahab had been very diligent in gathering a lot of it and likely made clothing for her and her household from it, and may have sold some as well (cp. Prov. 31:13, 34).