ויהי כי יראו המילדת את האלקים ויעש להם בתים .... (א-כא)
The Meforshim offer different explanations regarding the seder hapasuk - what is the connection between the beginning and the end? Additionally, what was the middah kneged midda here, between the fact that they feared Hashem and they received houses? Rashi learns that “batim” refer to the houses of Kehuna and Malchus. The Beis Halevi explains that since the Egyptians sought to kill the Jewish boys, the pure lineage of Klal Yisroel would’ve been eradicated. Thus, as a reward for saving the children, the Jewish midwives were rewarded with Kehuna and Malchus, which are dependent on lineage.
Perhaps we can offer another pshat. In Tehillim, the posuk says: יברך יראי ה'" "יברך את בית ישראל יברך את בית אהרן. Hashem blesses the houses of Yisroel and Aharon, however, when it comes to Yirei Hashem, the posuk omits the word “bais.” Why?
I heard an explanation as follows. In reference to Yidden, there is a bayis - a given. If the father is a Yisroel, the son is as well. With regard to a Kohen or a Levi, the same holds true. However, just because one’s father is a y’rei shamayim, it doesn’t mean that the children are de facto yirei shomayim. Yiras shamayim does not travel b’yerusha. Thus, the word “bais” is omitted. When Hashem saw to what degree the midwives feared only Him, and not Pharaoh,"ויעש להם בתים" - Hashem made a supernatural miracle and created houses of yirei shamayim! They had every excuse in the world, yet they lived with the premise of "שויתי ה' לנגדי תמיד" in the fullest sense of the words. Not only Moshe, Aharon and Miriam had this “bayis” bequeathed to them, but even the next generation. Chur, Miriam’s son, was able to stand up to Klal Yisrael and was moser nefesh at the time of eigel. The “bayis” of yirei shamayim that Miriam received served her grandchildren well.
The machshava here is that if a person lives his life being moser nefesh for Torah and mitzvos, without looking for loopholes, then BY EXAMPLE, yiras shamayim should automatically be transferred to his progeny, בסייעתא דשמיא.