אַחֲרֵ֨י יְהוָ֧ה אֱלֹהֵיכֶ֛ם תֵּלֵ֖כוּ וְאֹת֣וֹ תִירָ֑אוּ וְאֶת־מִצְוֺתָ֤יו תִּשְׁמֹ֙רוּ֙ וּבְקֹל֣וֹ תִשְׁמָ֔עוּ וְאֹת֥וֹ תַעֲבֹ֖דוּ וּב֥וֹ תִדְבָּקֽוּן׃
נאָך ה׳ אײַער גאָט זאָלט איר גײן, און פֿאַר אים זאָלט איר מוֹרא האָבן, און זײַנע געבאָט זאָלט איר היטן, און צו זײַן קָול זאָלט איר צוהערן, און אים זאָלט איר דינען, און אָן אים זאָלט איר זיך באַהעפֿטן.
Rashi
ואת מצותיו תשמורו HIS COMMANDMENTS YE SHALL KEEP — the Law of Moses,
Ramban
AFTER THE ETERNAL YOUR G-D SHALL YE WALK. This is a commandment that we follow His counsel, and of Him alone shall we inquire concerning every hidden thing and inquire concerning the future, as it is written, and she went to inquire of the Eternal;145Genesis 25:22. because the people come unto me to inquire of G-d.146Exodus 18:15. And so did the Israelites do with the prophets, [as it is said,] Is there not here a prophet of the Eternal, that we may inquire of the Eternal through him?;147II Kings 3:11. that the Eternal thy G-d may tell us the way wherein we should walk, and the thing we should do.148Jeremiah 42:3. And in the Sifre it is stated:149Sifre, R’eih 85. “After the Eternal your G-d [shall ye walk] — this refers to the cloud [of Glory].”150See Ramban to Numbers 9:19: “They did the will of G-d in following after the cloud [of Glory].” See also my Hebrew commentary here p. 406. This is as we have explained, that we are to hearken to the “voice” of His signs and follow His counsel.
Ibn Ezra
after God your God must you walk you must imitate His acts, to the best of your ability, and pursue His ways.