مُسْنَدُ أَحْمَدَ
Musnad Ahmad 1936
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated that Ibn "Abbas said: When the Messenger of Allah (ﷺ) came to Madinah, the people used to pay two or three years in advance for dates. He said: “whoever pays in advance, let him pay in advance for a specified measure and a specified weight, for a specified time.”
Musnad Ahmad 1937Sahih (Darussalam) [ al-Bukhari (2240) and Muslim (1604)]