Mark 3:22

And the scribes that came down from Jerusalem said, He hath Beelzebub, and, By the prince of the demons casteth he out the demons.

Come down from Jerusalem ... Geographically, they came up from Jerusalem, but the relative dignity of the priestly class in the Jewish capital was recognized in the idiom of that day which referred to all journeys as "up" to Jerusalem and "down" from Jerusalem.

Beelzebub ... This word is actually Beelzebub (English Revised Version (1885) margin) and has the meaning of "the dunghill god," "lord of flies" or "master of the house of demons"; but all such meanings may be ignored in this context, for "in the New Testament form the word means THE DEVIL."[8] This charge of the scribes was therefore that Christ was performing such wonderful works through being in league with the devil. The necessary inference from this charge points to the genuineness of Jesus' works, the charge itself being an admission that the miracles wrought by Jesus were altogether beyond the power of human nature and were therefore supernatural. The charge that Christ was in league with Satan was an exceedingly sinful one, and it occasioned the warning Jesus at once uttered.