Sunan Ibn Majah Book 16, Hadith 34
“When the Messenger of Allah (ﷺ) conquered Khaibar, he gave it (to its people) in return for half (of its yield).”
“When the Messenger of Allah (ﷺ) gave Khaibar to its people in return of its palm trees and land.
“I passed by some palm trees with the Messenger of Allah (ﷺ) and he saw some people pollinating the trees. He said: 'What are these people doing?' They said: 'They are taking something from the male part (of the plant) and putting it in the female part.' He said: 'I do not think that this will do any good.' News of that reached them, so they stopped doing it, and their yield declined. News of that reached the Prophet (ﷺ) and he said: 'That was only my thought. If it will do any good, then do it. I am only a human being like you, and what I think may be right or wrong. But When I tell you: “Allah (SWT) says,” I will never tell lies about Allah (SWT).' ”