inner strength

 Chazal tell us that Doeg was a gadol ha'dor, a brilliant talmid chacham, but his Torah was מן השׂפה לחוץ (Sanhedrin 106b).  It was all external trappings, but did not penetrate his soul.  Moshe Rabeinu, on the other hand, was the same on the inside as on the outside.  The Torah writes regarding the aron (Shmos 25:11) וצפית אתו זהב טהור מבית ומחוץ תצפנו, to plate it with gold on the inside, מבית, as well as on the outside.   בְּכׇל בֵּיתִי נֶאֱמָן הוּא Moshe was faithful not just on the outside, for show, but even מבית, even on the inside, throughout the depths of his being. 

The gemara in Taanis tells the story of חוני המעגל who people turned to to pray for rain.  Said Choni, בניך שמו פניהם עלי שאני כבן בית לפניך.  The reason Choni's tefilos were answered is because he had this midah of being faithful through and through, both on the inside, מבית -- he was  כבן בית -- and not just on the outside (Yismach Moshe).

I wanted to add my two cents that with this approach we can understand what the Torah tells (Shmos 1:21) us about the midwives of Bn"Y in Mitzrayim who refused to obey Pharoah's order to drown the babies:  וַיְהִי כִּי⁠ יָרְאוּ הַמְיַלְּדֹת אֶת⁠ הָאֱלֹקים וַיַּעַשׂ לָהֶם בָּתִּים  Through their yiras Shamayim the midwives built up their inner strength -- מבית -- and fortitude.