Abu Hurairah (May Allah be pleased with him) said:
The Messenger of Allah (ﷺ) said, "None of you should use the word Al-Karm for grapes, for Al-Karm is a Muslim (worthy of respect)."[Al- Bukhari and Muslim]Another narration is: "Verily, Al-Karm is the heart of a true believer."Another narration is: "People have named grapes as Al-Karm; verily, only the heart of a believer is Al-Karm."
App reference: Book 18, Hadith 230
Arabic/English book reference: Book 18, Hadith 1740