Consider 2 Kings, 16:1 in the Vulgate (2 Samuel in modern bibles):
Cumque David transisset paululum montis verticem, apparuit Siba puer Miphiboseth in occursum ejus, cum duobus asinis, qui onerati erant ducentis panibus, et centum alligaturis uvae passae, et centum massis palatharum, et utre vini.
The first bold phrase does include the cum, whereas the second does not, albeit, both are in the ablative. Is there any a priori reason why cum is omitted in the second phrase? More generally, are other prepositions omitted sometimes? If so, when are prepositions omitted?