SHEMA The requirement that it should be recited outside the Temple and before sunrise (Ber. v. 1 et passim) points to the origin of this usage. Its antiquity may be inferred from the fact that Josephus ("Ant." iv. 8, § 13) seems to ascribe it to Moses and that in traditional literature it is explained as a Biblical custom. At that time it must have been in existence for some centuries, for its genesis had been forgotten. http://www.jewishencyclopedia.com/view.jsp?artid=475&letter=L&search=Hallel psalm#ixzz0XKWtEOPQ so what do you think Jesus did in the Garden of Gethsemane ???