Hadith Q139
إِذْ لَوْ كَانَ السِّوَاكُ فَرْضًا أَمَرَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أُمَّتَهُ شَقَّ ذَلِكَ عَلَيْهِمْ أَوْ لَمْ يَشُقَّ. وَقَدْ أَعْلَمَ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَنَّهُ كَانَ آمِرًا بِهِ أُمَّتَهُ عِنْدَ كُلِّ صَلَاةٍ، لَوْلَا أَنَّ ذَلِكَ يَشُقُّ عَلَيْهِمْ. فَدَلَّ هَذَا الْقَوْلُ مِنْهُ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَنَّ أَمْرَهُ بِالسِّوَاكِ أَمْرُ فَضِيلَةٍ، وَأَنَّهُ إِنَّمَا أَمَرَ بِهِ مَنْ يَخِفُّ ذَلِكَ عَلَيْهِ دُونَ مَنْ يَشُقُّ ذَلِكَ عَلَيْهِ.
If the command to use the miswak had been obligatory, the Noble Prophet (peace be upon him) would have commanded the ummah to do so, whether it was difficult for them or not. Whereas the Noble Prophet (peace be upon him) has said: "Had I not considered it a hardship for my ummah, I would have commanded them to use it for every prayer." This statement of the Prophet (peace be upon him) indicates that his command to use the miswak is for virtue. And the command is for the one who finds it easy, not for the one who finds it difficult.
Hadith 139
Abu Hurairah (may Allah be pleased with him) reports that the Messenger of Allah (peace be upon him) said: "If I did not fear that I would put my Ummah into hardship, I would have commanded them to perform the ‘Isha prayer late and to use the miswak at the time of every prayer." Makhzumi did not mention the emphasis on delaying the ‘Isha prayer.
Hadith 140
Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: "If I had not feared that I would put hardship upon my Ummah, I would have commanded them to use the miswak with every ablution." Imam Abu Bakr (may Allah have mercy on him) says that this hadith is narrated in the Muwatta from Sayyiduna Abu Hurairah (may Allah be pleased with him) in this way: If it had not been difficult for your Ummah, you (peace and blessings be upon him) would have commanded them to use the miswak at every time of ablution. Imam Shafi'i (may Allah have mercy on him) and Bishr bin Umar have narrated it in the manner of Ruh's narration.