Muhammad said: The meaning of "jasu" (they entered/moved about) is: they wandered about; "al-jaws" is the seeking of something thoroughly. "And the promise was fulfilled."
قَالَ مُحَمَّدٌ: مَعْنَى (جَاسُوا): طَافُوا؛ الْجَوْسُ طَلَبُ الشَّيْءِ بِاسْتِقْصَاءٍ. ﴿وَكَانَ وَعدا مَفْعُولا﴾ كَائِنا