Genesis 44:30

Now 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;

Cross-reference

Genesis 44:31 spells out that Jacob would die if Benjamin fails to return, making the bond explicit.

Genesis 44:34 repeats Judah's fear of seeing disaster on his father, reinforcing the same life-bond.

Genesis 44:22 records Judah's earlier report that Jacob would die if Benjamin left, the same bond now referenced.

1 Samuel 18:1 uses the same 'soul knit' imagery for Jonathan and David, another deep personal attachment.