Charles Ellicott Commentary Isaiah 22:11

"ye made also a reservoir between the two walls for the water of the old pool. But ye looked not unto him that had done this, neither had ye respect unto him that purposed it long ago." — Isaiah 22:11 (ASV)

Ye made also a ditch between the two walls. —Better, a pond or pool, to form a reservoir for the city's supply. This was probably identical with the “pool of Hezekiah,” also known as the Birket-el-Batrak (“pool of the patriarchs”), between two walls, that to the north of Zion, and that which runs to the northeast around the Acra. During the rainy season this is supplied by the small conduit that runs from the upper pool along the surface of the ground, and then under the wall near the Joppa gate (Robinson, Researches, i., 437-439). The “old pool” was probably the pool of Siloam (John 9:7), or the king’s pool (Nehemiah 2:14).

Ye have not looked unto the maker thereof. —These material defenses, the prophet affirms, will avail little if they forget Him who was the true “builder and maker” of the city, and who alone can secure its safety.