Jacob said, ‘My sons, go and seek news of Joseph  and his brothers and do not despair of God’s mercy–  only the faithless despair of God’s mercy.’  

So they presented themselves before Joseph without knowing his real identity.  They explained that misfortune had afflicted their family  and pleaded for Joseph to be charitable.  "God", they said, "rewards the charitable".  Joseph replied by ‘Do you now realize what you did to Joseph and his brothers when you were ignorant?’  

The brothers were astounded and asked if he was Joseph and he said, ‘I am Joseph’.  They said God really did favour you over all of us; we were in the wrong.  Joseph replied that no reproach would be on them and may God forgive them.  Joseph then handed them his own shirt telling them to lay it over their blind father’s face and all would be well,  then he asked them to come back altogether.  Back at home Jacob was saying that he could smell Joseph,  and those around him looked upon him with derision thinking him lost in an old illusion.  

When the shirt was placed on Jacob’s face his eyesight returned and  he said, ‘Did I not tell you that I have knowledge from God that you do not have?’  The brothers asked their father to ask God to forgive them, and he replied that his Lord is the Most Forgiving and the Most Merciful.