'Inside' in the Bible

And the four living creatures, {each one} of them, had six wings apiece, full of eyes around and inside, and they do not have rest day and night, saying, "Holy, holy, holy [is] the Lord God All-Powerful, the one who was and the one who is and the one who is coming!"

And I saw in the right hand of the one who is seated on the throne a scroll, written inside and on the back, sealed up with seven seals.