(6-8) And if a Levite come.--The Levites with the priests were to receive forty-eight cities in Israel, with the suburbs (Numbers 35:7). There was as yet no provision made by which all could serve in turn at the tabernacle. When David divided them all into courses, priests, Levites, singers (and porters?) alike, there was no longer any need for this provision. The institutions of David prove its antiquity. The only case in history that illustrates it is that of the child Samuel. His father, Elkanah, was a descendant of Korah. He dwelt in Mount Ephraim, and came up to Shiloh year by year. But Samuel was dedicated by his mother to perpetual service there, and as long as the tabernacle continued in Shiloh, the child Samuel "ministered to the Lord before Eli the priest"--not as a priest, but as a Levite in attendance upon the priests.

Verses 6-8. - Only a portion of the Levites were engaged in the service of the sanctuary; the rest lived in their towns throughout the country. It might happen, however, that a Levite, moved by pious feeling, would come to the place of the sanctuary to worship there; and it is prescribed that such a one should fare as his brethren the Levites engaged in the service of the sanctuary fared; he should minister along with them, and share with them in the gifts of the worshippers; and this in addition to any private means he might have from the sale of his patrimony. Where he sojourned. The Levite, though not homeless, was regarded as only a sojourner in the land, inasmuch as the tribe had no inheritance (נַחֲלָח) there. They shall have like portions to eat; literally, they shall eat portion as portion, i.e. share and share alike. That which cometh of the sale of his patrimony; literally, his price upon [the house] of [his] fathers, i.e. the produce of the sale effected on the house he inherited from his ancestry (cf. Leviticus 25:33).

18:1-8 Care is taken that the priests entangle not themselves with the affairs of this life, nor enrich themselves with the wealth of this world; they have better things to mind. Care is likewise taken that they want not the comforts and conveniences of this life. The people must provide for them. He that has the benefit of solemn religious assemblies, ought to give help for the comfortable support of those that minister in such assemblies.And if a Levite come from any of thy gates out of Israel, where he sojourned,.... In any of the cities through the land, for they were dispersed all over the country, and employed in instructing and teaching the people; and, excepting the cities which were given them to dwell in out of the various tribes, they were but sojourners:

and come with all the desire of his mind unto the place which the Lord shall choose; the city of Jerusalem, where the temple would be built, and sacrifices offered, at which the Levites were assisting to the priests, and in various parts of the service of the sanctuary; and to which they are supposed to come with an hearty good will, with great eagerness of soul, and a vehement desire of being employed in the work of the Lord. Though Jarchi interprets it of a priest, that comes and offers his freewill offerings, or what he is obliged to, and even in a ward not his own; or, as otherwise expressed, of the priests that come to the feast, who offer in the ward, and serve in the offerings that come by virtue of the feast, as the additions of the feast, though it is not in their own ward; and indeed every priest was a Levite, though every Levite was not a priest; and the description of him after given, as standing ministering in the name of the Lord, best agrees with a priest.