1 Nephi 3:19; “And behold, it is wisdom in God that we should obtain these records, that we may preserve unto our children the language of our fathers.”
Nehemiah 13:24-26; “And their children spake half in the speech of Ashdod, and could not speak in the Jews’ language, but according to the language of each people. 25 And I contended with them, and cursed them, and smote certain of them, and plucked off their hair, and made them swear by God, saying, Ye shall not give your daughters unto their sons, nor take their daughters unto your sons, or for yourselves. 26 Did not Solomon king of Israel sin by these things? yet among many nations was there no king like him, who was beloved of his God, and God made him king over all Israel: nevertheless even him did outlandish women cause to sin.”
The language of the Jewish fathers was Hebrew, not “reformed Egyptian”.