And you were not covering [i.e., protecting] yourselves,1 lest your hearing testify against you or your sight or your skins, but you assumed that Allāh does not know much of what you do.
You did not used to hide when committing sins to a degree that your ears, eyes and skins cannot testify against you, because you did not believe in accountability, punishment or reward after death. Rather, you thought that Allah (may He be glorified) was not aware of many things you did and that it remained hidden from Him, so you were deceived.