Or HaChaim on Genesis 46:6/אור החיים על בראשית מ״ו:ו׳

1 ויקחו את מקניהם, They took their cattle, etc. This ought to have been reported in verse one when we are told about Jacob's whole family setting out on their journey to Egypt. Perhaps the brothers originally intended only to accompany their father and to see Joseph. Only after Jacob's dream did it become clear to them that G'd approved of their migration to Egypt until such time as it would please Him that they should return to their ancestral homeland (as I explained on verse 4). This is why they agreed only at this point to take their mobile possessions with them. The Torah also alludes to the fact that though the brothers may well have been aware that their journey would lead to their families' eventual exile in Egypt they did not rebel against what appeared to be G'd's decree.