قَالَ يَا بُنَيَّ لَا تَقْصُصْ رُؤْيَاكَ عَلَىٰ إِخْوَتِكَ فَيَكِيدُوا لَكَ كَيْدًا ۖ إِنَّ الشَّيْطَانَ لِلْإِنسَانِ عَدُوٌّ مُّبِينٌ (5)
(12:5) In response to this, his father said, "My little son, say nothing of this dream to your brothers, lest they should plot any evil scheme against you. *4 Be on your guard, for Satan is the avowed enemy of man.
*4) As the meanings of the dream were quite obvious, Prophet Jacob had a genuine fear that Joseph's ten step-brothers would become all the more envious of him when they would hear this: So he warned his righteous son not to mention his dream to his brothers, for he knew that those sons of his did not bear the moral character worthy of the sons of a Prophet, and, therefore, they were up to any evil design against him out of mere envy. As regards the dream, the "sun" in it was Prophet Jacob, the "moon" his wife, (Prophet Joseph's step-mother) and the "eleven stars" his eleven brothers.