It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: If I had not feared hardship for my ummah, I would have commanded them to use the miswak with every ablution. Hazrat Abu Huraira (may Allah be pleased with him) says: Since I heard this statement of the Noble Prophet (peace and blessings be upon him), I use the miswak before sleeping, after waking up, before eating, and after eating.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 9194
Hadith Gradingحکم دارالسلام:حديث صحيح، وهذا إسناد قوي،خ: 887، م: 252