Genesis 44:29 Meaning

27And thy servant my father said unto us, Ye know that my wife bare me two sons:

28And the one went out from me, and I said, Surely he is torn in pieces; and I saw him not since:

29And if ye take this also from me, and mischief befall him, ye shall bring down my gray hairs with sorrow to the grave.

30Now therefore when I come to thy servant my father, and the lad be not with us; seeing that his life is bound up in the lad's life;

31It shall come to pass, when he seeth that the lad is not with us, that he will die: and thy servants shall bring down the gray hairs of thy servant our father with sorrow to the grave.