Under the whole heaven; which is a synecdoche and an hyperbole, but is explained by the following words, which restrain the sentence to those nations that heard of them.
Related Commentaries of Deuteronomy 2:25
Deuteronomy 2:25
25 This day will I begin to put the dread of thee and the fear of thee upon the nations that are under the whole heaven, who shall hear report of thee, and shall tremble, and be in anguish because of thee.