"Faith" is the powerful season five premiere in which Gilgamesh (Tony Todd), possessed by Dahak, kills Iolaus (Michael Hurst). I've always loved the design of this episode. I think the set design, props and costumes are all really cleverly designed. They are all immediately identifiable as Sumerian. It was the cuneiform on the blade that first tipped me off about where this was used.
There are two guards in the episode who wear and use swords like these. The priest, Imuru (Ross Duncan) also uses one to kill a guard and attack Iolaus.
Iolaus himself uses one to free the captured Nebula (Gina Torres) so it's possible Michael Hurst used this prop!
A sword like this was also used in the following episode, "Descent," by Agenor (Tony Hopkins).
They would later appear in the eighth episode of the season, "Darkness Rising." My prop has two holes in the back where it was mounted on this weapons rack.