If you take the Bible to mean what it says and not what you interpret the words to mean then God does lie.
Gen.2;17 "But as for the tree of the knowledge of good and bad you must not eat from it ,for in the day you eat from it you will positively die."
They did not die in the day they ate from that tree like God said so he lied .
Adam and Eve would only have known what a day was from their experience just as we appreciate what a day is.