isaiah 30:6 The burden of the beasts of the south: into the land of trouble and anguish, from whence come the young and old lion, the viper and fiery flying serpent, they will carry their riches upon the shoulders of young asses, and their treasures upon the bunches of camels, to a people that shall not profit them. - Free Bible Online

      6. burden--the prophecy as to, &c. [MAURER]; so the Septuagint, the fresh inscription here marks emphatically the prediction that follows. Or, rather, Isaiah sees in vision, the ambassador's beasts burdened with rich presents travelling southwards (namely, to Egypt, Da 11:5, 6), and exclaims, Oh, the burden of treasure on the beasts! &c. (Ho 8:9; 12:1).
      land of trouble--the desert between Palestine and Egypt, destitute of water and abounding in dangerous animals (De 8:15; Jer 2:6).
      flying serpent-- (Isa 14:29), a species which springs like a dart from trees, on its prey.
      will carry--rather, present, "carry," namely, as presents to Egypt (1Ki 15:19).
      young asses--rather, "full-grown asses" [MAURER].

JFB.