הִשָּׁ֣מֶר לְךָ֔ פֶּֽן־תַּעֲזֹ֖ב אֶת־הַלֵּוִ֑י כָּל־יָמֶ֖יךָ עַל־אַדְמָתֶֽךָ׃ (ס)
你要謹慎,在你住在你土地上的一切日子裡,不可丟棄利未人。
Rashi
השמר לך TAKE HEED TO THYSELF [LEST THOU FORSAKE THE LEVITE] — This is intended in addition to the positive command expressed in the previous verse, to attach to it (the neglect of the Levite) a negative command, also.
Rabbeinu Bahya
כל ימיך על אדמתך, “all your days on your land.” The specific command not to abandon the Levite is applicable only in the Holy Land. Levites in the Diaspora do not enjoy preferred status regarding receipt of charity from their brethren.