Комментарий к Шмот 18:8

ויספר משה לחתנו AND MOSES RELATED TO HIS FATHER-IN-LAW [ALL THAT THE LORD HAD DONE] — in order to allure his heart that he might attach him to the Torah (Mekhilta d'Rabbi Yishmael 18:8).

את אשר עשה ה' לפרעה ולמצרים על אודות ישראל. A reference to G’d performing vengeance as the avenger of His people. Compare Deuteronomy 32,41 for similar syntax used by Moses. when he quotes G’d as saying אשיב נקם לצרי, “vengeance will I wreak on My foes.” This referred to the Egyptians experiencing G’d’s retribution on their own bodies when they drowned in the sea. In Psalms 78,49 the psalmist describes 4, resp. 5 stages of G’d’s anger which the Egyptians had to experience before they died. Tthat verse is the subject of detailed analysis in the Haggadah shel Pessach. These events proved that G’d had chosen the Jewish people as His most treasured possession among the nations.

ויספר משה לחתנו, Moses told his father-in-law, etc. Although the Torah told us that Yitro had heard all that G'd had done, there may have been some details which he had not heard about. Alternatively, Yitro had assumed that what he had heard previously was grossly exaggerated; Moses now explained to him that what he heard was true to the last detail. It is also possible that until Moses told him otherwise Yitro had been under the impression that the Israelites were still vassals of the Egyptians, not totally free. Moses told him of the slaying of the guardian angel of the Egyptians, something that Yitro could not have heard about from any other source as only the Israelites had seen the "dead" guardian angel (Zohar second volume page 52). Once Yitro heard about this he knew that the Egyptians did no longer have any hold over the Israelites.