﴿ يَٰبَنِىَّ ٱذْهَبُوا۟ فَتَحَسَّسُوا۟ مِن يُوسُفَ وَأَخِيهِ وَلَا تَا۟يْـَٔسُوا۟ مِن رَّوْحِ ٱللَّهِ ۖ إِنَّهُۥ لَا يَا۟يْـَٔسُ مِن رَّوْحِ ٱللَّهِ إِلَّا ٱلْقَوْمُ ٱلْكَٰفِرُونَ ﴾

“[Hence,] O my sons, go forth and try to obtain some tidings of Joseph and his brother; and do not lose hope of God's life-giving mercy: verily, none but people who deny the truth can ever lose hope of God's life-giving mercy.”

Jacob was heartbroken on losing his two very dear sons. But at the same time he pinned his hopes on the Grace of God. He was certain that Joseph’s dream predicted the future and that it would definitely come true. That is why he asked his sons to go and search for Joseph and also to try to have Benjamin released.