Genesis 44:2

And put my cup, the silver cup, in the sack’s mouth of the youngest, and his corn money. And he did according to the word that Joseph had spoken.

Cross-reference

In Genesis 42:15, Joseph demands Benjamin be brought — here (44:2) he plants the cup as a further test after that condition is met.

In Genesis 42:16, Joseph imprisons them to test their honesty — here (44:2) he plants the cup to test them further. Both part of same testing scheme.

In Genesis 42:20, Joseph commands they bring Benjamin — here (44:2) after they have, he sets the trap with the cup.

Genesis 42:25 records Joseph secretly placing money in sacks — the same pattern and test method used here with the silver cup.