This link is interesting. There is a warning not to see what you want to see, {scroll down to sub title "The Paradise Show"} but this kind of imagery appears frequently on these weapons. We know the back ground and setting, also that the peoples are Muslim, that weapons, warriors, jihad, death and martyrdom often go hand in hand with faith and paradise. Mottos and talismans of a religous nature are common on edged weapons the world over. It is not unreasonable to consider exploring possible links to "higher?" depictions of paradise in Islamic art and architecture.
http://www.sonic.net/~tallen/palmtree/ip.html