They conspired against him to keep him away from his father by killing him or taking him away to a distant land. And the brothers knew that was they were planning was a great sin, but they conspired against him anyway and vowed to repent afterwards. “and after that you will be righteous folk”.
The lesson for parents is being just when dealing with children.
And the lesson for the children is to know that parents don’t have control over their hearts and feelings, as in the hadith: “This is my oath in what I have, so don’t blame me for what I don’t have.”
( إِذۡ قَالُواْ لَيُوسُفُ وَأَخُوهُ أَحَبُّ إِلَىٰٓ أَبِينَا مِنَّا وَنَحۡنُ عُصبَةٌ إِنَّ أَبَانَا لَفِى ضَلَـٰلٍ۬ مُّبِينٍ (٨) ٱقۡتُلُواْ يُوسُفَ أَوِ ٱطۡرَحُوهُ أَرۡضً۬ا يَخۡلُ لَكُمۡ وَجۡهُ أَبِيكُمۡ وَتَكُونُواْ مِنۢ بَعۡدِهِۦ قَوۡمً۬ا صَـٰلِحِينَ (٩) قَالَ قَآٮِٕلٌ۬ مِّنۡہُمۡ لَا تَقۡتُلُواْ يُوسُفَ وَأَلۡقُوهُ فِى غَيَـٰبَتِ ٱلۡجُبِّ يَلۡتَقِطۡهُ بَعۡضُ ٱلسَّيَّارَةِ إِن كُنتُمۡ فَـٰعِلِينَ)
يوسف 12: 8-10
و الدرس للأبناء أن يعرف أن الوالدين لا يملكون قلوبهم كما في الحديث: “هذا قسمي فيما أملك فلا تؤاخذني فيما لا أملك”