This is a type of Salam sale (sale with advance payment) however, it was concluded without the conditions of Salam. Salam is concluded on items that are possessed in hand with the conditions that measurement, weight, arm-length, amount, type, and any other factors which affect a difference in the price must be known along with the ability to make delivery on a fixed date. What you have mentioned in your question is concluding a sale of an item that is not possessed as
the man agreed to give him a return on his money in the form of honey from a certain bee-keeper. In addition, he did not specify a weight or date of delivery. This is similar to what the people of
Al-Madinah used to do. They would make advance payment on fruit from certain palm trees. When the Prophet (peace be upon him) arrived at
Al-Madinah he forbade this type of transaction as it entails Gharar sale (fraudulent transaction where details about the sold item are unknown or uncertain) for fear that the palms could be ruined and not yield fruit.
Ibn Hajar mentioned in his book, Fath Al-Bari, (vol. 4, (Part No. 14; Page No. 109) p. 433) that, "
It has been reported by
Ibn Al-Mundhir that the majority of scholars agreed upon the prohibition of Salam sale with regard to selling a specific orchard because it is Gharar".
It was reported by
Ibn `Abbas (may Allah be pleased with them) that,
When the Messenger of Allah (peace be upon him) arrived at
Al-Madinah, the people used to pay in advance the price of fruits to be delivered within one or two years. Thereupon he (peace be upon him) said: Whoever pays money in advance, should pay it for known specified weight and measure to a fixed date.
(Agreed upon by Al-Bukhari and Muslim).
Therefore, this kind of Salam sale mentioned in the question is not permissible as it does not meet the conditions. The bee-keeper should return the money to its owner. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.