Musnad Ahmad 31:422

Muhammad ibn Ja‘far narrated to us, Sa‘id narrated to us, from Qatadah, from Sa‘id ibn al-Musayyib, from Abu Sa‘id al-Khudri, that the Messenger of Allah (may Allah bless him and grant him peace) was brought fresh, moist dates. The dates of the Prophet of Allah (may Allah bless him and grant him peace) were dry dates that had some dryness in them. He said: "From where did you get this date?" They said: "This is date we bought, a sa‘ for two sa‘s of our dates." The Prophet (may Allah bless him and grant him peace) said: "That is not permissible. Rather, sell your dates, then buy what you need."