It is narrated from Sayyiduna Sahl bin Hunayf (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) ordered (the giving of) charity, and a man brought clusters of this inferior date and placed them there. The Messenger of Allah (peace and blessings be upon him) came out and said: "Who brought this?" Then whoever came would throw down (there) whatever he had brought, so this verse was revealed: "O you who believe, spend of the good things you have earned and of what We have brought forth for you from the earth, and do not aim at the bad of it to spend (in charity)" [Surah al-Baqarah: 267]. And on that day he (peace and blessings be upon him) forbade that Ju'rur and Lawn Ibn al-Hubayq be taken in charity. Al-Zuhri said: "These are two kinds of the dates of Madinah." And Abbad said that Sufyan said: "Al-sakhl means shis (spoiled, defective dates)."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5546