I heard Layth narrating from Ibn Shihab that whenever it was mentioned to him that the Prophet had prohibited fasting on Saturday, Ibn Shihab would say, "This is a Homsi hadith."
حدثنا عبد الملك بن شعيب
سمعت الليث يحدث عن ابن شهاب أنه كان إذا ذكر له أنه نهى عن صيام يوم السبت يقول ابن شهاب هذا حديث حمصي
No references are available.
[Its isnad is sahih] It has already been referenced. See the previous hadith: 24210