Sahih al-Bukhari 1488
Sahih al-Bukhari · Book 24: Obligatory Charity Tax (Zakat) · Whoever sold his fruits, trees, land or crops and gave Zakat from some other property
Narrated Anas bin Malik:
حَدَّثَنَا قُتَيْبَةُ ، عَنْ مَالِكٍ ، عَنْ حُمَيْدٍ ، عَنْ أَنَسِ بْنِ مَالِكٍ ـ رضى الله عنه ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم نَهَى عَنْ بَيْعِ الثِّمَارِ حَتَّى تُزْهِيَ، قَالَ حَتَّى تَحْمَارَّ.
Allah's Messenger (ﷺ) forbade the selling of fruits until they were ripe. The Prophet (p.b.u.h) added, "It means that they become red ."