"This month shall be for you." It shall be turned over to you. R. Yehoshua b. Levi said, "It's like a king who had a horologue. When he looked at it, he would know what time of day it was. When his child grew up, he turned over his horologue to them. So too did the Holy One of Blessing, up until this point, calculate the months and years "by my hand". But from this point onwards, behold I am giving it over into your hands: "This month shall be for you." ... If the earthly court declares: ‘Today is Rosh Hashana!’ The Holy One Blessed Be He proclaims to the angels: ‘Erect a podium! Call the prosecuting attorneys; call the defense attorneys! My children have declared: Today is Rosh Hashana!’ If the earthly court determines to delay the holiday, the Holy One Blessed Be He declares to the heavenly Angels: ‘Remove the podium! Remove the prosecuting attorneys; remove the defense attorneys! My children have decided to postpone the holiday for a day." What is the reason? (Teh 81:5) "[If] it is a law [according] to Yisrael, [then it is] a ruling of the God of Ya'akov."