Mishkat al-Masabih 21 Foods كتاب الأطعمة 37

وَعَن المِقدامِ بن معدي كرب عَنِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «كيلوا طَعَامك يُبَارك لكم فِيهِ» . رَوَاهُ البُخَارِيّ

Al-Miqdam b. Ma’dikarib reported the Prophet as saying, “If you measure out your food* you will be blessed in it.” *This is said to refer to such matters as buying and selling, and taking care that suitable portions are given to one’s children. Bukhari transmitted it.