We learn that centaurs are particularly afraid of fire.
Merkus: Well, 'Mr Immigrant', I'm about to brain you!
Salmoneus: Wait! (raises two fingers and hums)
Merkus: Why are you humming?
Salmoneus: I'm finding your internal flower. Hmmmmmm. Ah! It's a weed! (pokes him in the eyes)
Salmoneus: (after Hercules defeats the Cretans) Yes!
Hercules: (pulling his hands away from Salmoneus' slap) Is there some reason you're trying to slap my hand?
Salmoneus: I saw it in an athletic contest once. It's a way for winners to congratulate each other.
Hercules: Why don't they just say nice job or congratulations?
Salmoneus: You need more fun in your life.
Deric: (seeing Lyla materialize) You're here! But how?
Lyla: (turning to Hercules) Your father Zeus.
Hercules: He can undo the evil of men. It's the malice of the Gods he has trouble with.
Kevin Sorbo has commented that he wasn't keen on Lyla suddenly being returned to life at the end of the story, and that it wasn't necessary.
This was the first episode produced for the second season. They did it so that Lucy Lawless could film her scenes as Lyla just before joining her own show Xena: Warrior Princess full time.
The studio laid out a few ground rules for Rob Tapert as to what he was allowed to do and what he couldn't. One thing they said he couldn't do was kill a mother in the teaser. Rob's response? "Watch me." The result was "Outcast".
Disclaimer: No centaurs were harmed during the production of this motion picture.
Salmoneus: Lyla, Lyla, does she remind you of anyone we both know?
Hercules: Come to think of it, she looks a little like Xena.
This is an allusion to the fact that Lucy Lawless played both Lyla and Xena on the show.
Salmoneus: (taking care of young Kefor) Not potty trained, hmm? Well, if he can handle the Augean Stables...
This is a reference to one of Hercules Twelve Labors. He was ordered to clean the stables of King Augeas, which hadn't been mucked out in years. He diverted a river through it to wash the dung away, but then demanded payment. King Eurystheus, when he heard about the compensation, ordered Hercules to perform another Labor for him, since he was supposed to be doing them solely for King Eurystheus' benefit.
Hercules' speech about whomever is not different casting the first stone is like the biblical "let he among us without sin cast the first stone".