Allah says:
﴿ إِنَّ اللَّهَ يُحِبُّ التَّوَّابِينَ وَيُحِبُّ الْمُتَطَهِّرِينَ ﴾
“Indeed, Allah loves those who repent and loves those who purify themselves.”
[Surah al-Baqarah 2:222]
Imam Ibn Kathir رحمه الله mentioned that this includes
both physical and spiritual purification.
The Messenger of Allah ﷺ said:
« السِّوَاكُ مَطْهَرَةٌ لِلْفَمِ مَرْضَاةٌ لِلرَّبِّ »
“The Miswak cleanses the mouth and pleases the Lord.”
Reference: Musnad Ahmad: 6/47
Reference: Sunan an-Nasa’i: 5/12

Authenticated by al-Albani
Aishah رضي الله عنها said:
« كَانَ النَّبِيُّ ﷺ إِذَا دَخَلَ بَيْتَهُ بَدَأَ بِالسِّوَاكِ »
“When the Prophet ﷺ entered his house, he would begin with the Miswak.”
Reference: Sahih Muslim: 253
The Prophet ﷺ said:
« لَوْلَا أَنْ أَشُقَّ عَلَى أُمَّتِي لَأَمَرْتُهُمْ بِالسِّوَاكِ عِنْدَ كُلِّ صَلَاةٍ »
“If I had not feared hardship for my Ummah, I would have commanded them to use the Miswak before every prayer.”
Reference: Sahih al-Bukhari: 887
Reference: Sahih Muslim: 252
Aishah رضي الله عنها said:
“The last thing the Messenger of Allah ﷺ did was to use the Miswak.”
Reference: Sahih al-Bukhari: 4438
This shows the
great importance of the Miswak even at the time of death.
The
best Miswak is from the
Arak tree (Salvadora persica), because:
• It is what the Prophet ﷺ used
• It is explicitly mentioned by scholars
• It has proven medicinal benefits
Ibn Qudamah رحمه الله said:
“The best Miswak is from the Arak tree, and anything else may be used if Arak is unavailable.”
[al-Mughni]