According to the Bible, Jesus received 39 lashes. This was in accord with the maximum amount of lashes allowed by Jewish law. The number was based on the theory that 39 was the maximum amount of lashes that a person could endure without dying.
The number is likely to emphasize the torture Jesus endured on the way to the cross. Lashes were inflicted with a flagrum, which was a whip constructed of leather straps with metal and glass attached to them. The act of whipping prisoners prior to crucifying them was called scouring. Despite Jesus's crucifixion being accredited to the Jews, crucifixion was not a known punishment of the Jews. It was a Roman punishment.