حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم نَهَى عَنْ بَيْعِ الثِّمَارِ حَتَّى يَبْدُوَ صَلاَحُهَا نَهَى الْبَائِعَ وَالْمُشْتَرِيَ ‏.‏

Yahya related to me from Malik from Nafi from Ibn Umar that theMessenger of Allah, may Allah bless him and grant him peace, forbadeselling fruit until it had started to ripen. He forbade thetransaction to both buyer and seller. Translation Not Available

Book Ref: Muwatta Imam Malik Book 31 Hadith 1302
Web Ref:  Muwatta Imam Malik Book 31 Hadith 10