It is narrated from Sayyiduna Wa'il bin Hujr (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said: "None of you should ever say: 'Karam,' rather you should say 'Hablah,' meaning grapes."
Hadith Referenceالادب المفرد / كتاب الأقوال / 795
Hadith Gradingالألبانی:صحيح
Hadith Takhrij«صحيح : أخرجه مسلم ، كتاب الألفاظ : 2248»
Explanation & Benefits
Shaykh Maulana Usman Muneeb
Benefits and Issues: The point is that do not call grapes "karm," rather refer to them as "hablah" or "‘inab." In one narration, it is stated that the true "karm" is the heart of the believer. (For further details, see Hadith 770)
Source: Fadlullah al-Ahad: Urdu Commentary on al-Adab al-Mufrad, Page: 795