Calvin's Commentaries, Vol. 5: Harmony of the Law, Part III, tr. by John King, [1847-50], at sacred-texts.com
Deut. 10:8, 9
8. At that time the Lord separated the tribe of Levi, to bear the ark of the covenant of the Lord, to stand before the Lord to minister unto him, and to bless in his name, unto this day.
8. In tempore illo separavit Jehova tribum Levi: ut gestaret Arcam foederis Jehovae, ut staret coram Jehova ad ministrandum ei, et ad benediecudum in nomine ipsius usqae ad diem hanc.
9. Wherefore Levi hath no part nor inheritance with his brethren; the Lord is his inheritance, according as the Lord thy God promised him.
9. Idcirco non fuit ipsi Levi portio et haereditas cum fratribus suis: Jehova est haereditas ejus, quemadmodumdixit ei Jehova Deus tuus.
8. At that time the Lord separated the tribe of Levi Moses does not exactly observe the order of time in the chapter from which this passage is taken, since he deemed it sufficient to collect here and there what was required to complete his general exhortation. The object indeed of the recital of this history was, lest any should attempt to overthrow God’s invioable decree in their pride and audacity; and therefore, in order that the dignity of the tribe of Levi may not beget envy, he testifies that God is its author. The clause, “unto this day,” seems to refer to those instances in which God had manifested His favor towards the Levites, lest any similar rivalry should hereafter arise. The rest has been expounded elsewhere.