When he came to the tower - The Chaldee, Septuagint, Syriac, and Arabic understand the word עפל ophel, which we translate tower, as signifying a secret, dark, or hiding place. He was doing a deed of darkness, and he sought darkness to conceal it. He no doubt put them in a place little frequented, or one to which few had access besides himself. But the prophet's discerning spirit found him out.
The tower - Rather, “the hill,” the well-known hill by Elisha‘s house. The hill interrupted the view in the direction taken by Naaman, and Gehazi dismissed Naaman‘s servants at this point lest they should be seen from his master‘s residence.