וְכִֽי־יָבֹ֨א הַלֵּוִ֜י מֵאַחַ֤ד שְׁעָרֶ֙יךָ֙ מִכָּל־יִשְׂרָאֵ֔ל אֲשֶׁר־ה֖וּא גָּ֣ר שָׁ֑ם וּבָא֙ בְּכָל־אַוַּ֣ת נַפְשׁ֔וֹ אֶל־הַמָּק֖וֹם אֲשֶׁר־יִבְחַ֥ר יְהוָֽה׃
E se un levita viene da una qualsiasi delle tue porte fuori da tutto Israele, dove soggiorna, e viene con tutto il desiderio della sua anima nel luogo che l'Eterno sceglierà;
Rashi on Deuteronomy
וכי יבא הלוי AND IF A LEVITE COME […AND MINISTER] — One might think that Scripture speaks of a “Levite” in the usual sense of the word (i.e. of a לוי and not of a כהן)! Scripture, however, goes on to state, (v. 7) “And he shall minister [in the name of the Lord]”; thus the Levites must be excluded for they are not fit for (not entitled to) service in the Temple (Sifrei Devarim 168:1).
Rashbam on Deuteronomy
וכי יבא הלוי, a priest who does not belong to the roster of priests performing Temple service on that day in the courtyard of the Temple in Jerusalem
Siftei Chakhamim
Perhaps it is literally to the Levite that Scripture refers?, etc. I.e. an actual descendant of Levi, to exclude a kohein. Or perhaps the verse includes a kohein also, because a kohein is also a descendant of Levi? [In proof of this latter suggestion] the Torah therefore teaches, “He shall perform the service,”, etc.