פּירוש אויף דברים 10:21

הוא תהלתך, “He is your glory;” you are to boast about having Him as your G-d, as will be explained forthwith.

HE IS THY PRAISE, AND HE IS THY G-D. The meaning thereof is that He should be your [sole object of] praise, that you are to devote all your praise to Him, praising Him always and not to give His glory to another, neither His praise to graven images,²⁶⁷Isaiah 42:8. nor to the gods and lords mentioned.²⁵⁷Verse 17. Or he may be stating: “He is thy praise, for through Him you are praised above all peoples,” similar in expression to the verses, For Thou art the glory of their strength;²⁶⁸Psalms 89:18. O Eternal, my strength, and my stronghold.²⁶⁹Jeremiah 16:19.

He is your glory i.e., it is appropriate for you to glorify in Him, because He has done awesome things for you.