مختصر صحيح بخاري
Mukhtasar Sahih Bukhari
Book of Jumu'ah (Friday Prayer)
Using miswak on Friday is Sunnah.
Sayyiduna Anas (may Allah be pleased with him) says that (on one occasion) the Messenger of Allah (peace and blessings of Allah be upon him) said: "I have taught you a great deal about (the virtues of) the miswak."
