מדרש אויף במדבר 36:5

(Exodus, Ibid. 16) "And they said to Moses: Speak, you, with us, and we will hear, (and let G–d not speak with us, lest we die.") We are hereby apprised that they lacked the strength to receive no more than ten pronouncements, viz. (Devarim 5:22) "If we continue hearing the voice of the L–rd our G–d, we will die," but (Ibid. 6) you draw near," and we will hear. At that time, Israel merited the L–rd's establishing prophets for them, as it is written (Ibid. 18:18) "A prophet shall I raise up for them, etc." I was destined to set up a prophet for them (later), but their merit preempted it, viz. (Ibid. 17) "And the L–rd said to me: They have done well in speaking as they did" (viz. Ibid. 16). Happy are those in whose words the L–rd concurs! And thus is it written (Numbers 27:7) "Rightly do the daughters of Tzelafchad speak," (Ibid. 36:5) "Rightly does the scribe of the sons of Yosef speak." Happy are those in whose words the L–rd concurs! And thus is it written (Ibid. 14:20) "I have forgiven because of your (Moses') words.

(Bamidbar 27:6-7) "And the L-rd said to Moses: Rightly do the daughters of Tzelafchad speak": The daughters of Tzelafchad have claimed well, for thus is this section written before Me on high. Happy is the man whose words the L-rd acknowledges. Similarly, (Ibid. 36:5) "Rightly does the tribe of the sons of Joseph speak." Similarly, (Ibid. 14:20) "And the L-rd said: I have forgiven according to your words." The peoples of the world are destined to say this: "Happy is the man whose words the L-rd acknowledges." "Given shall be given to them the holding of an inheritance": This is the inheritance of their father. "in the midst of the brothers of their father": This is the inheritance of the father of their father "and you shall pass over the inheritance of their father to them": This is the portion of the first-born — whence we are apprised that the daughters of Tzelafchad took three portions: that of their father, that of their father's father, and the double portion of the first-born. R. Eliezer b. Yaakov says: Also that of their father's brothers, it being written "Given shall be given to them."

Indeed, the tribe of Benjamin used to speak [a coded language] (written in the hint of the year 775). There were no festive days for the Israelites like the fifteenth of Av and Yom Kippur. Regarding Yom Kippur, it is a day of forgiveness and atonement [the day the second tablets were given]. But why is the fifteenth of Av [considered special]? Rav Yehuda said, it is the day when the tribes were allowed to intermarry. What is the scriptural source for this? "This is the thing that the Lord has commanded concerning the daughters of Zelophehad." This matter only applies to this generation. Rav Nachman said, it was the day when the deaths in the desert ceased, as our Master said, as long as the deaths in the desert were not finished, there was no communication with Moses. As it is written, "And it came to pass when all the men of war had completely ceased to die." And it is written, "And the Lord spoke to me, saying, 'You have gone through enough of this.'"