It was narrated that Ibn 'Umar said: "The Messenger of Allah said: "Volume is to be measured according to the system of the people of Al-Madinah, and weight is to be measured according to the system of the peole of Makkah."' (Sahih) This is the wording of Ishaq (one of the narrators)"
SahihSahihDaifBook 44 · Hadith 146