וַיִּשְׁמַ֞ע יִתְר֨וֹ כֹהֵ֤ן מִדְיָן֙ חֹתֵ֣ן מֹשֶׁ֔ה אֵת֩ כָּל־אֲשֶׁ֨ר עָשָׂ֤ה אֱלֹהִים֙ לְמֹשֶׁ֔ה וּלְיִשְׂרָאֵ֖ל עַמּ֑וֹ כִּֽי־הוֹצִ֧יא יְהוָ֛ה אֶת־יִשְׂרָאֵ֖ל מִמִּצְרָֽיִם׃
Now Jethro, the priest of Midian, Moses’father-in-law, heard of all that God had done for Moses, and for Israel His people, how that the LORD had brought Israel out of Egypt.
Read halakhic rulings (Jewish law) on Exodus 18:1: and classical halakhic sources.