Adam Clarke on Acts 10:12

All manner of four-footed beasts, etc. - Every species of quadrupeds, whether wild or domestic; all reptiles, and all fowls. Consequently, both the clean and unclean were present in this visionary representation: those that the Jewish law allowed to be sacrificed to God, or proper for food; as well as those which that law had prohibited in both cases: such as the beasts that do not chew the cud; fish which have no scales; fowls of prey and such others as are specified in Lev 11:1, etc., where see the notes.