E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Hip! Hip! Hurrah!
Hip is said to be a notarica, composed of the initial letters of Hierosolyma Est Perdita. Henri van Laun says, in Notes and Queries, that whenever the German knights headed a Jew-hunt in the Middle Ages, they ran shouting Hip! Hip! as much as to say Jerusalem is destroyed. (See NOTARICA.)
Timbs derives Hurrah from the Sclavonic hù-raj (to Paradise), so that Hip! hip! hurrah! would mean Jerusalem is lost to the infidel, and we are on the road to Paradise. These etymons may be taken for what they are worth. The word hurrah! is a German exclamation also.
Now, infidel, I have thee on the hip (Merchant of Venice); and again, Ill have our Michael Cassio on the hip (Othello), to have the whip hand of one. The term is derived from wrestlers, who seize the adversary by the hip and throw him.