Adam Clarke on 1 Kings 4:28

And dromedaries - The word רכש rechesh, which we translate thus, is rendered beasts, or beasts of burden, by the Vulgate; mares by the Syriac and Arabic; chariots by the Septuagint; and race-horses by the Chaldee. The original word seems to signify a very swift kind of horse, and race-horse or post-horse is probably its true meaning. To communicate with so many distant provinces, Solomon had need of many animals of this kind.