Genesis 44:31
It 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.
Cross-reference
Genesis 44:29 says the same thing — losing Benjamin brings Jacob's gray hairs to Sheol. This reinforces the plea.
In verse 30, Jacob's life is bound to Benjamin's; verse 31 then concludes that losing Benjamin would kill Jacob — direct cause-effect.
Genesis 37:26 shows Judah proposing to sell Joseph — contrasting his earlier indifference with his current protectiveness.
Genesis 37:27 has Judah selling Joseph — a stark contrast to his willingness to sacrifice himself for Benjamin.
Genesis 37:35 has Jacob refusing comfort, saying he will go to Sheol mourning Joseph — the same fate predicted for losing Benjamin.
In Genesis 42:38, Jacob first said 'bring down my gray hairs with sorrow' — Judah now repeats his father's exact fear about losing Benjamin.