Abu Hurairah reported,
The Prophet ﷺ said, "One of you may give in charity a single date earned from honest income, placing it in its rightful place. Allah receives it with His right hand and continues to nurture it for him, just as one of you raises his young foal, until it becomes like a mountain or even greater than a mountain."
Ahmad 8961
Sahihحدثنا عفان قال حدثنا وهيب حدثنا سهيل عن أبيه
عن أبي هريرة
عن النبي ﷺ قال إن أحدكم ليتصدق بالتمرة من الكسب الطيب فيضعها في حقها فيليها الله بيمينه ثم ما يبرح فيربيها كأحسن ما يربي أحدكم فلوه حتى تكون مثل الجبل أو أعظم من الجبل
Its isnad is sahih. The imams narrated it with a different wording, with the wording, "No one gives charity from good earnings..." Bukhari narrated it in the Book of Zakat, "Allah does not accept charity from ill-gotten gains," and Muslim in the Book of Zakat, "The acceptance of charity from good earnings," number 64, and Tirmidhi in the Book of Zakat, "The merit of charity," 40/3, number 661, and he said, hasan sahih, and Nasai, 357/5, and Ibn Majah, 1842.8941m - My father said, and he also narrated to us, meaning Affan, from Khalid, I think he is Wasiti, with his isnad and its meaning, except that he said, "So Allah accepts it 
with His right hand." Sahih (8941m). Its isnad is sahih, and it is the same hadith as the previous one, differing only in what Ahmad mentioned. Except that Affan narrated it there from Wahib from Suhayl, while here he narrated it from Khalid from Suhayl.