Another matter, “Yitro…heard,” that is what is written: “The stranger does not stay the night outside” (Job 31:32). Just as it is written earlier in the portion [beginning]: “This is the statute of the paschal offering, [no foreigner shall eat from it]” (Exodus 12:43), until: A proselyte who married the daughter of an Israelite and begot a daughter, and the daughter went and married a legitimate priest and bore a son, that son is fit to be the High Priest.15The midrash has referenced an earlier passage (Shemot Rabba 19:4), stated in conncection to Exodus 12:43.
That passage cites the verse in Job and states that if a proselyte married the daughter of an Israelite, etc. He stands and sacrifices atop the altar; the result is that the proselyte is inside and the Levite is on the outside. That is, “The stranger does not stay the night outside.” “I opened my doors for the guest” (Job 31:32), this is Yitro, for whom the Holy One blessed be He brought down manna, as it is stated: “He commanded the skies above and opened the doors of heaven” (Psalms 78:23).