12 Ben-Hadad heard this message while he and the kings were drinking in their tents,a and he ordered his men: “Prepare to attack.” So they prepared to attack the city.

Read 1 Kings 20:12 Using Other Translations

And it came to pass, when Benhadad heard this message, as he was drinking, he and the kings in the pavilions, that he said unto his servants, Set yourselves in array. And they set themselves in array against the city.
When Ben-hadad heard this message as he was drinking with the kings in the booths, he said to his men, "Take your positions." And they took their positions against the city.
Ahab’s reply reached Ben-hadad and the other kings as they were drinking in their tents. “Prepare to attack!” Ben-hadad commanded his officers. So they prepared to attack the city.