Why was Yisro so interested in inviting Moshe to his house?
Rashi: When his daughters told him that the water rose to meet him, he realized that he must be a descendant of Yaakov. 1
Seforno: He was simply instructing his daughters (or granddaughters) to perform Chesed (Hachnasas) Orchim with the man who had performed Chesed with them.
See Bereishis 47:10. Refer to 2:20:2:1.
What did Yisro mean when he said, "Let him eat bread"?
Rashi #1: He meant that perhaps he will marry one of them.
Rashi #2 (to Koheles 11:1) 1 : 'When Yisro said to his daughters, 'Invite him and let him eat bread!", he took him to be an Egyptian, whom he would never see again. Yet see what happened; Moshe first became his son-in-law, then a king, and in the end, he brought Yisro under the wings of the Shechinah, and his sons and grandsons merited to sit in the Lishkas ha'Gazis (on the Sanhedrin). 2
Sanhedrin 104a: 'How great is Legimah (serving a guest a bit of food) - As a reward for instructing his daughters to invite Moshe and offer him something to eat, his descendants sat (on the Sanhedrin) in the Lishkas ha'Gazis!
"Cast your bread upon the waters, for in the course of time you will find it" (Koheles 11:1).
Da'as Zekenim (to 2:15): Since Yisro accepted to do a Mitzvah, it did not leave him. He accepted a fugitive who fled; and later Ya'el, Eshes Chever ha'Keni (who came from Yisro) killed the enemy general Sisera, who had fled from Barak (Shoftim 4).
Yisro invites Moshe to eat bread; the Gemara (Sanhedrin 103b) writes that in this merit, he was able to later join Am Yisrael. What is the great merit in sharing food with others?
Maharal #1 (Gevuros Hashem Ch. 20, p. 92): Hashem is the Source (Ikar) who gives sustenance to the world, just like the trunk of a tree spreads sustenance to all its branches. The branches that are closest to the trunk convey sustenance to those that are further away. By giving sustenance to others, one becomes closer to Hashem.
Maharal #2 (ibid.): This world operates such that the transcendent (Nivdal) bestows, and the physical (Chomer) continually receives. 1 By giving food to others, one emulates the ways of Hashem. 2
Maharal (Nesivos Olam, Nesiv ha'Torah Ch. 4, p. 20): This explains why a Talmid Chacham must despise gifts (see Chulin 44b); in the existential sense, the intellect (Sechel) and the spiritual give, and the physical (Chomer) realm receives.
Maharal (ibid.): By becoming a giver (a Nosen, a Mashpi'a), a person emulates his Creator and becomes closer to Hashem; for the world's very existence is from the good that Hashem grants.
QUESTIONS ON RASHI
Rashi writes: "He realized that [the man must be] a descendant of Yaakov, for the waters ascended towards him." Why is this phenomenon specifically associated with Yaakov?
Gur Aryeh #1: 'The entire world is blessed through Yaakov and his descendants' (Bereishis 28:14). Thus, the waters ascended to bring their blessing as Moshe approached.
Gur Aryeh #2: Yaakov bestowed the blessings "of the deep that crouches below" (Bereishis 49:25); 1 which is represented by a spring.
Maharal (Gevuros Hashem Ch. 20, p. 91): In order to bestow such a blessing, Yaakov must have already received it himself! Indeed, the waters of the well-springs would rise to meet Yaakov (presumably, on the occasion that he met Rachel by the well, in Charan (Bereishis 29:10). According to Targum Yonasan (ibid.) that well continued to overflow for the entire twenty years that Yaakov was there (CS)). A spring as a source of blessing represents the eternal survival of Yaakov's children (also refer to Bereishis 24:17:1.1:3).
Rashi writes: "... For the waters ascended." The Midrash derives this from the girls' wording, "he watered the flocks" (2:19) - i.e., not just our own flocks, but even those of the shepherds - since the water had risen for everyone. Mizrachi asks - But perhaps it means that Moshe took the efforts, and watered also the shepherds' flocks, manually?
Gur Aryeh: Yisro had asked his daughters how they returned home so fast (2:18); to which they answered, "An Egyptian man saved us... and watered the flocks" (2:19). If this meant only that Moshe watered the shepherds' flocks as well (after having tended to the girls' flocks), it would be irrelevant to Yisro's question as to how they got home so fast. Rather, they were telling Yisro how he watered the flocks - that the waters miraculously rose to meet him - and that is why they returned home early.
Rashi writes: "'Why, then, did you abandon the man?' - He realized that [the man] is a descendant of Yaakov, for the waters ascended towards him." How does Rashi's comment fit with his title? Is that the only reason that they should not abandon him?
Maharal (Gevuros Hashem Ch. 20, p. 91): The miracle indicated that Moshe was a descendant of Yaakov; who is attached to the source of blessing, and (his nation) will never cease or be destroyed. It was such a people that Yisro wanted to be attached to. 1
At first, via his daughters by marriage; later Yisro himself joined Klal Yisrael. (CS)
Rashi writes: "[The man must be] a descendant of Yaakov...." Similarly, Yisro uses the term "Ayo;" which the Midrash (Yalkut Shimoni) compares to the term "Ayeh [Sarah Ishtecha]" (Bereishis 18:9). Yisro said, 'Perhaps the man descends from Sarah, by whom all the world is blessed!' What is the deeper meaning in this comparison to Sarah?
Maharal (Gevuros Hashem Ch. 20, p. 91): When it was time for the angels to inform Avraham and Sarah that they would have a child, Sarah was not to be seen. The angels asked 'Where is Sarah?,' to highlight her Tzeni'us (modesty) and thus endear her to Avraham (Rashi to Bereishis 18:9). Yisro realized that Moshe was exhibiting this same trait of modesty. He did not follow and run after the girls, to tell Yisro of the great favor he had done for him, but rather he remained behind. Blessing only rests upon that which is inward and hidden; Yisro hoped that his children would join with this source of blessing.
Rashi writes: "'[Invite him,] and he will eat bread' - [I.e.,] perhaps he will marry one of you...." The Midrash cites this as an example of Lashon Nekiyah, refined speech. Why is such refinement important?
Maharal (Nesivos Olam, Nesiv ha'Tzenius Ch. 3, p. 108): Disgraceful speech shows the depravity of the speaker, whereas refined speech indicates a person with intellect (as opposed to physicality).