Genesis 42:17

Into ward three days. Joseph had solemnly charged his brothers (v. 15) to send one of their number back to Canaan to fetch Benjamin. Their apparent unwillingness to do this, in the knowledge that Jacob would not consent, led Joseph to send them all to jail for three days. This was ostensibly done in consequence of their unwillingness to agree to his proposal, but in reality to test them further. He had languished in prison for approximately three years, as the result of their inhuman treatment; he inflicted on them a confinement of only three days.