All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
We have not come across this wording in the reliable books of the scholars that we have at hand but this statement is mentioned on many sites on the internet and it is attributed to ‘Ali without attributing that to any authentic book of the scholars.
Nonetheless, the raisins have many benefits among which is strengthening the memory. Ibn Al-Qayyim said in “The Prophetic Medicine”: “Az-Zuhri said: “Whoever wants to memorize the Hadeeth, let him eat raisins.”
Allaah Knows best.