God tells us to have no OTHER gods before Him, not *strange* gods, because that leaves room for familiar gods.
Here you can look it up in the Hebrew yourself.
http://biblehub.com/text/exodus/20-3.htm
Hebrew Transliterated
20:3 L’a YHYH-LK ‘aLHYM ‘aChUrYM ‘yL-PhNY.
Latin Vulgate
20:3 non habebis deos alienos coram me