וְעַתָּ֗ה אִם־שָׁמ֤וֹעַ תִּשְׁמְעוּ֙ בְּקֹלִ֔י וּשְׁמַרְתֶּ֖ם אֶת־בְּרִיתִ֑י וִהְיִ֨יתֶם לִ֤י סְגֻלָּה֙ מִכָּל־הָ֣עַמִּ֔ים כִּי־לִ֖י כָּל־הָאָֽרֶץ׃
און אַצונד, אױב צוהערן װעט איר צוהערן צו מײַן קָול, און איר װעט היטן מײַן בונד, װעט איר זײַן מײַן באַזונדער אײגנס פֿון צװישן אַלע אומות; װאָרום צו מיר געהערט די גאַנצע ערד.
Sefer HaChinukh
It is from the roots of the commandment from the angle of the simple understanding that God, may He be blessed, wanted to inform His nation that everything is His; and in the end everything will return to those to whom He wanted to give it at first — for the earth is His, as it is written (Exodus 19:5), “for all the earth is Mine.” And with this commandment of the counting of forty-nine years, they will distance themselves from stealing land of their fellows and they will not covet it in their hearts; in that they know that everything returns to the one that God wishes it to be his.