Rashi on Deuteronomy 12:19/רש"י על דברים י״ב:י״ט

1השמר 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.

2על אדמתך [TAKE HEED TO THYSELF LEST THOU FORSAKE THE LEVITE] UPON THY GROUND — but in exile (outside the Holy Land) you are not admonished as regards him more than as regards the poor of the ordinary Israelites (Sifrei Devarim 74:9; Talmud Yerushalmi Horayot end).