Genesis 46:26

All the souls that came with Jacob into Egypt, which came out of his loins, besides Jacob’s sons’ wives, all the souls were threescore and six;

The number records sixty-six direct descendants who accompanied Jacob into Egypt. The count includes only those who sprang from Jacob himself. The wives of Jacob's sons are expressly left out of the reckoning. The figure therefore does not represent every member of the larger household that made the journey.