Musnad Ahmad 8:77

Ibn Numayr narrated to us, Malik ibn Anas narrated to us, Abdullah ibn Yazid, the freed slave of al-Aswad ibn Sufyan, narrated to me, from Abu Ayyash, from Sa’d ibn Abi Waqqas, who said: The Messenger of Allah (peace and blessings of Allah be upon him) was asked about [exchanging] fresh dates for dried dates. He said: "Does the fresh date not decrease when it dries?" They said: "Yes." So he disliked it.