Musnad Ahmad 31:67

Muhammad ibn Idris—meaning al-Shafi‘i—narrated to us, he said: Malik informed us, from Dawud ibn al-Husayn, from Abu Sufyan, the freed slave of Abu Ahmad, from Abu Sa‘id al-Khudri: "That the Messenger of Allah (may Allah bless him and grant him peace) forbade *al-muzabanah* and *al-muhaqalah*." *Al-muzabanah* is the buying of fruit with dates while they are still on the palm trees. *Al-muhaqalah* is the renting of land for wheat. *** 11053 - ‘Abdullah ibn Muhammad narrated to us—Abu ‘Abd al-Rahman said: And I heard it from ‘Abdullah ibn Muhammad ibn Abi Shaybah—Abu Khalid al-Ahmar narrated to us, from al-A‘mash, from al-Dahhak al-Mashriqi, from Abu Sa‘id al-Khudri, from the Prophet (may Allah bless him and grant him peace) that he said: "Is one of you unable to recite a third of the Qur’an in a night?" He said: That was difficult for his companions, so they said: "Who is capable of that?" He said: "Recite 'Say, He is Allah, [who is] One' (Qul Huwa Allahu Ahad), for it is a third of the Qur’an."