Ata (may Allah have mercy on him) said concerning the saying of Allah Almighty: "And give its due on the day of its harvest." [Surah al-An'am: 141]: Whoever comes to you and asks for something, you give him something, and it is not zakah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7506