Jamieson, Fausset and Brown on Judges 19:15

15. when he went in, he sat him down in a street of the city--The towns of Palestine at this remote period could not, it seems, furnish any establishment in the shape of an inn or public lodging-house. Hence we conclude that the custom, which is still frequently witnessed in the cities of the East, was then not uncommon, for travellers who were late in arriving and who had no introduction to a private family, to spread their bedding in the streets, or wrapping themselves up in their cloaks, pass the night in the open air. In the Arab towns and villages, however, the sheik, or some other person, usually comes out and urgently invites the strangers to his house. This was done also in ancient Palestine (Ge 18:4; 19:2). That the same hospitality was not shown in Gibeah seems to have been owing to the bad character of the people.