It is narrated from Abdullah bin Umar, may Allah be pleased with him, that the Prophet ﷺ forbade selling fruits until the fear of calamity has passed. Uthman said, I asked Abdullah, may Allah be pleased with him, what is that time? He replied, when ripeness becomes apparent.
Hadith Referenceمسند الإمام الشافعي / كتاب البيوع / 1422
Hadith Takhrijصحیح اخرجه البيهقى 5 /300 - وفى المعرفة السنن والآثار له (3392) - واحمد: 2/ 42 ، 50 - والطحاوي في شرح المعاني : (23/4)۔