John Gill Commentary Deuteronomy 10:9

"Wherefore Levi hath no portion nor inheritance with his brethren; Jehovah is his inheritance, according as Jehovah thy God spake unto him.)" — Deuteronomy 10:9 (ASV)

Wherefore Levi has no part nor inheritance with his brethren, &c.] In the division of the land of Canaan, because being separated to the service of the sanctuary, he had no leisure to plough and sow, as Jarchi observes:

the Lord is his inheritance, as the Lord your God promised him; not in a spiritual sense, for so the Lord was an inheritance and portion of other Israelites; though these being taken off of worldly employments, and devoted to sanctuary service, might have more communion with God than others; but in a temporal sense, provision being made particularly by tithes, which were the Lord's, for their maintenance; and so the Targums of Onkelos and Jonathan paraphrase the words; ``gifts which the Lord gave him are his inheritance;'' see (Numbers 18:20Numbers 18:21) .