مختصر صحيح مسلم
Mukhtasar Sahih Muslim
Issues of Fasting
Prohibition of fasting only on Fridays.
Abu Huraira (may Allah be pleased with him) reports that the Messenger of Allah (peace and blessings of Allah be upon him) said: No person should fast specifically on Friday, unless he fasts a day before it or a day after it as well.