Dhu al-Qarnayn had built had been breached, he dispatched me, saying, “Go there, examine it, and bring me word of its condition.” He placed fifty men under my command, provided us with provisions, and gave us two hundred mules to carry the supplies.
We set out from Sāmarrāʾ bearing his letter to Ishaq, who was then in Tiflis. Ishaq wrote to the Ṣāḥib al-Sarīr, who in turn wrote to the king of the Alans; the king of the Alans wrote to Fīlānshāh; and Fīlānshāh wrote on our behalf to the king of the Khazars. The latter assigned five guides to accompany us. From his court we travelled for twenty-six days and then came upon a stretch of black, foul-smelling land where the air reeked like vinegar; we crossed it in ten days. Next we reached deserted, ruined cities; we marched among them for twenty-seven days. When we asked our guides about these towns, they said, “These are the places that Gog and Magog used to raid until they laid them waste.”
We then arrived at a line of forts near the Wall, inhabited by people who spoke both Arabic and Persian, were Muslims, recited the Quran, and maintained mosques and elementary schools. They questioned us, and we replied, “We are envoys of the Commander of the Faithful.” They were astonished and kept asking, “The Commander of the Faithful—truly?” We said, “Yes.” They asked, “Is he an old man or a youth?” We answered, “A youth.” They asked, “Where does he reside?” We replied, “In Iraq, in a city called Sāmarrāʾ.” They said, “We have never heard of such a place.”
From there we reached a smooth mountain bare of greenery, opposite another mountain that had been cut through by a valley one hundred cubits wide. On either side of the valley, abutting the mountain, we saw two jambs, each twenty-five cubits wide, with ten cubits of their height protruding beneath, jutting out in front of the gate. The whole structure was built of iron bricks set in copper, fifty cubits thick. Fixed upon each jamb was an additional course ten cubits high and five wide. Above the lintel the same iron-brick masonry rose to the summit of the mountain, towering as far as the eye could see; on top of that were iron battlements with two projecting horns, each interlocking with the other.
There stood an iron gate with two leaves, shut fast, each leaf one hundred cubits wide, one hundred cubits high, and five cubits thick. Upon it was a lock seven cubits long and as thick as an arm-span, and some two man-heights above it was another bolt whose length—