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.