Sforno on Numbers 14:28/ספורנו על במדבר י״ד:כ״ח

1חי אני נאם ה' אם לא וגו, whenever we find two successive negatives this is equivalent to a positive statement. [the word אם as well as the word לא are each understood as a negative. Ed.] כאשר דברתם באזני, a reference to verse 2 in which the people are reported as wishing that they had died already in Egypt and inverse 3 when they had prematurely bemoaned their wives and children as becoming part of the Canaanites booty in the war they anticipated losing. G’d also refers to what the spies themselves had said when they described the land of Canaan as “consuming its inhabitants” (13,32). G’d would see to it now that all these statements would become self-fulfilling prophecies.

2כן אעשה לכם; not all at once but at intervals. This is what prompted the psalmist in Psalms 106,26 to say: “So He raised His hand in oath to make them fall the wilderness; to disperse their offspring among the nations and scatter them throughout the land.” Also the prophet Ezekiel sees in the present decree something that had repercussions throughout the ages when he said (Ezekiel 20,23) “also I raised My hand in an oath already in the desert, saying I will scatter them among the nations.” [our author sees in the punishment meted out at this time a parallel to that meted out at the time of the sin of the golden calf where G’d had reserved the right to spread the retribution throughout history in order not to have to wipe out the people then and there as they had deserved. Ed.]