Sayyiduna Ibn Umar (may Allah be pleased with them both) said: The Messenger of Allah (peace and blessings be upon him) forbade the sale of fruits before they ripen. He forbade both the seller and the buyer from this sale.
Hadith Takhrijاس روایت کی سند قوی اور حدیث متفق علیہ ہے۔ دیکھئے: [بخاري 2194] ، [مسلم 1534] ، [أبويعلی 5415] ، [ابن حبان 4981، وغيرهم]
Brief Explanation
(The Explanation of Hadith 2590)
The meaning of the ripening of fruits is that redness or yellowness appears in them and the capability of ripening becomes evident; at this time, their buying and selling is permissible, but not before this.
Qastallani rahimahullah said: In every thing, the manifestation of its capability of ripening «حَتَّييَبْدُوَصَلَاحُهَا» means that the quality which is predominantly sought after becomes present in it.
From this hadith, it is understood that selling unripe fruits and produce is prohibited; only when signs of ripening appear is it correct to sell fruits, because it is possible that an unripe fruit or produce may develop some disease and the buyer may suffer a loss.