From Sahih Muslim (Hadith 3912):
Jabir b. Abdullah (Allah be pleased with them) reported Allah's Messenger (ﷺ) forbidding Muzabana and Muhaqala, and Mukhabara, and the sale of fruits until they are ripe. I (the narrator) said to Sa'id (the other narrator):What does ripening imply? He said: It meant that they become red or become yellow and are fit for eating
Reference: Muslim 3912