And he commanded the steward of his house, saying: ‘Fill the men’s sacks with food, as much as they can carry, and put every man’s money in his sack’s mouth. And put my goblet, the silver goblet, in the sack’s mouth of the youngest, and his corn money.’ And he did according to the word that Joseph had spoken. (Genesis 44:1–2)

וַיְצַו אֶת אֲשֶׁר עַל בֵּיתוֹ לֵאמֹר: מַלֵּא אֶת אַמְתְּחֹת הָאֲנָשִׁים אֹכֶל כַּאֲשֶׁר יוּכְלוּן שְׂאֵת, וְשִׂים כֶּסֶף אִישׁ בְּפִי אַמְתַּחְתּוֹ. וְאֶת גְּבִיעִי – גְּבִיעַ הַכֶּסֶף – תָּשִׂים בְּפִי אַמְתַּחַת הַקָּטֹן, וְאֵת כֶּסֶף שִׁבְרוֹ. (בראשית מ"ד, א-ב)

Why choose his divination goblet to incriminate Benjamin in theft?

The choice was deliberate. Joseph used intimate family history to construct an account plausible to his brothers, echoing an earlier pattern and provoking déjà vu.

In a similar situation, fleeing Haran, Benjamin’s mother Rachel stole her father’s teraphim. Like Joseph’s goblet, they served divination. Their theft endangered Jacob’s family by increasing Laban’s motivation to pursue; without divine intervention it might have ended badly (Genesis 31:29).

Joseph constructed a scenario echoing Rachel: theft of a divination object producing danger of pursuit. He confronted the brothers with a familiar family pattern, Rachel’s children unintentionally precipitating a crisis threatening everyone.

His plan was to make brothers familiar with Rachel’s theft accept her son’s repeating a similar act in similar circumstances, seeing a problematic tendency in her family (Abarbanel on Genesis 44:1). He sought to dull their response and weaken their will to resist, enabling him to retain Benjamin without real opposition.