I was passing through a palm grove with the Messenger of Allah ﷺ when he saw some people pollinating the palm trees. He asked, "What are these people doing?"They replied, "They take pollen from the male and place it into the female."He said, "I do not think that does any good."Word of this reached them, so they abandoned the practice and came down from the trees. When this reached the Prophet ﷺ, he said, "It was only an opinion. If it does any good, then do it. I am only a human being like you, and opinion can be wrong or right. But whatever I tell you that Allah has said, I will never lie about Allah."
حدثنا علي بن محمد حدثنا عبيد الله بن موسى عن إسرائيل عن سماك أنه سمع
مررت مع رسول الله ﷺ في نخل فرأى قوما يلقحون النخل فقال ما يصنع هؤلاء قالوا يأخذون من الذكر فيجعلونه في الأنثى قال ما أظن ذلك يغني شيئا فبلغهم فتركوه فنزلوا عنها فبلغ النبي ﷺ فقال إنما هو الظن إن كان يغني شيئا فاصنعوه فإنما أنا بشر مثلكم وإن الظن يخطئ ويصيب ولكن ما قلت لكم قال الله فلن أكذب على الله
Muslim narrated it in Fadail, chapter on the obligation to comply with what he said as a matter of sharia, etc., hadith 2361, the hadith of Simak, through him.