Law hidden from tzadik

 Bamidbar Rabbah (21:12) AND MOSES BROUGHT THEIR CAUSE. Some hold that the law was hidden from Moses. There are cases where righteous men have boasted of some matter connected with a precept and G-d weakened their power. You find that David boasts: Thy statutes have been my songs, as much as to say that they are easy and familiar like songs. Said G-d ‘By your life! You will in the end err in a matter that children read in the Scripture! ' When he brought up the ark he erred and put it on a cart; as it says, And they set the ark of G-d upon a new cart. The ark suspended itself in the air and the cows beneath it slipped. Uzzah drew near to support it, And G-d smote him there for his error, for an error in learning amounts to presumption. And David was displeased, because the Lord had broken forth upon Uzzah. G-d said to him: ' Did you not say, "Thy statutes have been my songs"? Have you not learned: But unto the sons of Kohath he gave none, because the service of the holy things belonged unto them: they bore them upon their shoulders David began to reflect: The Lord our G-d made a breach upon us, for that we sought Him not according to the ordinance . It was the same with Moses. Because he had boasted: The cause that is too hard for you ye shall bring unto me, and I will hear it, He diminished his mental powers. It is like the case of a money-changer who said to his apprentice: ‘If you are brought selaiim to exchange into small coins exchange them, but if pearls come, bring them to me.’ A bead of glass was brought to him and he took it to his master. His master, however, went to consult someone else about it! It is the same here. Moses had said: ’The cause that is too hard for you ye shall bring unto me.’ When the daughters of Zelophehad, however, came, He concealed the law from him, AND MOSES BROUGHT THEIR CAUSE BEFORE THE LORD. THE DAUGHTERS OF ZELOPHEHAD SPEAK RIGHT. This, He meant, is the law! G-d said to him: ' Did you not say, "The cause that is too hard for you ye shall bring unto me"? The law with which you are unacquainted is decided by the women!