A.T. Robertson Commentary Acts 10:15

"And a voice [came] unto him again the second time, What God hath cleansed, make not thou common." — Acts 10:15 (ASV)

Make not thou common (συ μη κοινου). Note emphatic position of συ (thou). Do thou stop making common what God cleansed (εκαθαρισεν). The idiom of μη with the present active imperative κοινου means precisely this. Peter had just called "common" what God had invited him to slay and eat.