אֶ֕רֶץ אֲשֶׁר־יְהוָ֥ה אֱלֹהֶ֖יךָ דֹּרֵ֣שׁ אֹתָ֑הּ תָּמִ֗יד עֵינֵ֨י יְהוָ֤ה אֱלֹהֶ֙יךָ֙ בָּ֔הּ מֵֽרֵשִׁית֙ הַשָּׁנָ֔ה וְעַ֖ד אַחֲרִ֥ית שָׁנָֽה׃ (ס)
네 하나님 여호와께서 권고하시는 땅이라 세초부터 세말까지 네 하나님 여호와의 눈이 항상 그 위에 있느니라
Rashi on Deuteronomy
אשר ה' אלהיך דרש אתה [A LAND] WHICH THE LORD THY GOD CARETH FOR — But does He not care for all lands, as it said, (Job 38:26) “[Who hath cleft a way for the lightning of the thunder …] to cause rain even on a land where no man is"? But, if one can say so of God, He cares for that land alone, but through the care which He bestows on it, He cares also for all other lands with it (Sifrei Devarim 40:1).
Sforno on Deuteronomy
דורש אותה, to carefully scrutinize the deeds of its inhabitants to determine if they are deserving the rain or not. Therefore, you should remain aware of the fact that
Or HaChaim on Deuteronomy
אשר ה׳ אלוקיך דרש, "which the Lord your G'd enquires after (all the time)." Moses emphasises the word אלוקיך, "your G'd" to remind us that the excellence of this land is conditional on the mutually exclusive relationship between Israel and its G'd. If Israel were to find itself in exile due to its sins, the land would not prove excellent for whoever would dwell in it after Israel would be expelled.