Albert Barnes Commentary 2 Kings 7:10

"So they came and called unto the porter of the city; and they told them, saying, We came to the camp of the Syrians, and, behold, there was no man there, neither voice of man, but the horses tied, and the asses tied, and the tents as they were." — 2 Kings 7:10 (ASV)

They called unto the porter ... and told them — The word “porter” is used like our “guard,” and the meaning here is not that the lepers called to any particular individual, but that they roused the body of men who were keeping guard at one of the gates.