וְחָרָ֨ה אַף־יְהוָ֜ה בָּכֶ֗ם וְעָצַ֤ר אֶת־הַשָּׁמַ֙יִם֙ וְלֹֽא־יִהְיֶ֣ה מָטָ֔ר וְהָ֣אֲדָמָ֔ה לֹ֥א תִתֵּ֖ן אֶת־יְבוּלָ֑הּ וַאֲבַדְתֶּ֣ם מְהֵרָ֗ה מֵעַל֙ הָאָ֣רֶץ הַטֹּבָ֔ה אֲשֶׁ֥ר יְהוָ֖ה נֹתֵ֥ן לָכֶֽם׃
e la rabbia dell'Eterno si accenderà contro di te, e chiuse il cielo in modo che non ci sia pioggia e che la terra non dia il suo frutto; e perite rapidamente dalla buona terra che l'Eterno vi dà.
Rashi on Deuteronomy
את יבולה [THE GROUND WILL NOT GIVE] ITS יבול — it will not yield even as much as what you have brought (יבול) to it (even the same quantity of seed you have sown in it), just as it is said, (Hag. 1:6) “You sow much, but bring in little” (Sifrei Devarim 43:28; cf. Rashi on Leviticus 26:20).
Sforno on Deuteronomy
and as a result of such a development ואבדם מהרה, from hunger, which is a more painful death than dying by the sword.. Therefore, remain on guard!
Or HaChaim on Deuteronomy
לא תתן את יבולה, "it will not yield its produce." Although Moses had already said that G'd would lock the heavens he repeated that the earth would not yield its produce to tell the people that even if they were to plant their fields adjacent to rivers and wells the earth would not produce a harvest.