Cephas is Greek? Maybe I am mistaken. Thanks.
Actually I’d say we were both mistaken.
It seems it’s actually Aramaic, not Greek or Hebrew.
http://biblehub.com/greek/2786.htm
However, the word, “Képhas”, is Greek, which is what’s used in all the manuscripts we have today. The word “Képhas” is derived from the Aramaic “Cephas” which means “rock” in other words. “Képhas” means “rock” in Greek, etc.