Al-Dhahabi reported: Abu Hamid al-Tusi, may Allah have mercy on him, said, “Know that the religion has two conditions. The first is to abandon what has been forbidden. The other is to perform righteous acts of obedience. Abandoning what is forbidden is more difficult than being obedient. Everyone is capable of being obedient, but none are capable of abandoning lowly desires except the truthful. For this reason the Prophet, peace and blessings be upon him, said: The true emigrant is one who emigrates away from evil, and the one striving in jihad for the sake of Allah is he who strives against his desires.”
Source: Siyar A’lām al-Nubalā’ 1420
عن الذهبي قَالَ أَبُو حَامِد الطُّوسِيُّ رحمه الله اعْلَمْ أَنَّ الدِّينَ شَطْرَانِ أَحَدُهُمَا تَرْكُ الْمَنَاهِي وَالْآخَرُ فِعْلُ الطَّاعَاتِ وَتَرْكُ الْمَنَاهِي هُوَ الْأَشَدُّ وَالطَّاعَاتُ يَقْدِرُ عَلَيْهَا كُلُّ أَحَدٍ وَتَرْكُ الشَّهَوَاتِ لَا يَقْدِرُ عَلَيْهَا إِلَّا الصِّدِّيقُونَ وَلِذَلِكَّ قَالَ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ الْمُهَاجِرُ مَنْ هَجَرَ السُّوءَ وَالْمُجَاهِدُ مَنْ جَاهَدَ هَوَاهُ
1420 سير أعلام النبلاء الذهبي الطبقة السادسة والعشرون