Judges 4:19

Gave him milk to drink; either because she had not water in her tent, and pretended fear of discovery or some inconvenience if she went out to fetch it; or as a signification of greater respect; or as a likely mean to cast him into a sleep, which she desired and designed; to which end possibly she might mix something with it to cause sleep, which she could not so conveniently have done with water. Covered him, upon pretence of hiding him, but really to dispose him to sleep.