וְשָׁמַרְתָּ֨ אֶת־הַמִּצְוָ֜ה וְאֶת־הַֽחֻקִּ֣ים וְאֶת־הַמִּשְׁפָּטִ֗ים אֲשֶׁ֨ר אָנֹכִ֧י מְצַוְּךָ֛ הַיּ֖וֹם לַעֲשׂוֹתָֽם׃ (פ)
Guarda por tanto los mandamientos, y estatutos, y derechos que yo te mando hoy que cumplas.
Rashi
היום לעשותם [WHICH I COMMANDED THEE] TO-DAY TO DO THEM — to do them to-day, but only in the time to come — in the future world — to receive the reward for them (Eruvin 22a).
Chizkuni
ושמרתם את המצוה, “You shall therefore keep the commandment;” your observing His commandments will be appropriate as a repayment for G-d keeping His promises to the forefathers.”
Ibn Ezra
Therefore keep Just as God keeps the covenant, so must you keep His commandments.