Hadith 4:242
Hammad ibn Khalid narrated to us, from Mu'awiyah ibn Salih, from al-'Ala' ibn al-Harith, from Mu'adh: That he used to come to his family after the sun had passed its zenith and say, "Do you have any lunch?" They would excuse themselves to him, so he would say, "I am fasting the remainder of my day." It would be said to him, "You fast the end of the day?" He would reply, "Whoever does not fast its end has not fasted its beginning."
حدثنا حماد بن خالد عن معاوية بن صالح عن العلاء بن الحارث عن معاذ أنه كان يأتي أهله بعد الزوال فيقول عندكم غداء فيعتذرون إليه فيقول اني صائم بقية يومي فيقال له تصوم آخر النهار فيقول من لم يصم آخره لم يصم أوله