מדרש על במדבר 27:15

(Exodus 16:15) "And the children of Israel saw it, and each said to his neighbor 'man hu.'" As one says to his friend "mah hu" ("What is it?") The expounders of metaphors said: Israel called it "man" ("sustenance"), as it is written (Ibid.) "And Moses said to them: This is the 'bread' that the L-d has given to you to eat." (viz. Ibid. 4) R. Yehoshua says: Moses said it to the elders, and the elders, to all of Israel. From here, R. Yossi and R. Shimon say: Israel "stuffed" themselves like horses at that time, it being written here "to eat," and elsewhere (re the manna) (Psalms 78:25) "Each man ate the bread of abirim." Read it not "abirim," but "eivarim" ("limbs") — bread that is absorbed by the limbs. He said to them: This "man" that you are eating is being absorbed by your limbs. (Psalms, Ibid.) "He sent them sustenance to satiety": This refers to Joshua the son of Nun, for whom the manna descended over and against all of Israel. Others say: On his limbs it descended, and from his limbs he took it to eat. Thus, "The bread of abirim was eaten by man ("ish")" (i.e., Joshua, viz. Numbers 27:15)

What was Moses’ reason for making this request after declaring the order of inheritance? Just this, that when the daughters of Tzelophehad inherited from their father, Moses reasoned: The time is right for me to make my own request. If daughters inherit, it is surely right that my sons should inherit my glory.

15 (Numb. 27:16) “[…] Let the Lord, the God of the spirits [of all flesh], appoint”: Anyone who comes to seek the needs of the community is as if he comes forcefully. (Numb. 27:16) “Let the Lord appoint”: What reason did [Moses] have to request this need after the ordering of inheritance? It is simply that since he saw the daughters of Zelophehad inherit the properties of their father, Moses said, “See it is the time for me to claim my needs. If daughters inherit, it is [also] proper for my sons to inherit my glory.” The Holy One, blessed be He, said to him (in Prov. 27:18), “’He who tends a fig tree will enjoy its fruit.’ Your sons sat [with] their own [concerns] and were not involved with Torah [study]. [Whereas] Joshua served you much and showed you much honor. And he got up early to your house of meeting and left late. He arranged the benches and spread out the mats. Since he served you with all of his ability, he is worthy to serve Israel, so as not to lose his compensation.” (Numb. 27:18) “Take Joshua bin Nun,” in order to fulfill what is stated (in Prov. 27:18), “He who tends a fig tree will enjoy its fruit.”