This means that the servant was watching for enemies while guarding at the city wall. AT: "who was guarding" or "who was guarding at the city wall" (See: [[rc://en/ta/man/translate/figs-idiom]])
# raised his eyes
Here the servant looking up at something is spoken of as if he lifted up his eyes. AT: "looked up" (See: [[rc://en/ta/man/translate/figs-metaphor]])