“I heard Iyas bin 'Abd Muzani say - when he saw people selling water: 'Do not sell water, for I heard the Messenger of Allah (ﷺ) forbidding selling of water.' ”
Sunan Ibn Majah Book 16, Hadith 41
← Previous Hadith That he asked for a salt flat called the Ma'rib Dam to be given to him, and it was given to him. Then Aqra bin Habis At-Tamimi came to the Messenger of Allah (ﷺ) and said: “O Messenger of Allah (ﷺ), I used to come to the salt flat during the Ignorance period and it was in a land in which there was no water, and whoever came to it took from it. It was (plentiful) like flowing water.” So the Messenger of Allah (ﷺ) asked Abyad bin Hammal to give back his share of the salt flat. He said: “I give it to you on the basis that you make it charity given by me.” The Messenger of Allah said: “It is a charity from you, and it is like flowing water, whoever comes to it may take from it.”(One of the narrators) Faraj said: “That is how it is today, whoever comes to it takes from it.” He said: “The Prophet (ﷺ) gave him land and palm trees in Jurf Murad instead, when he took back the salt flat from him.”

Sunan Ibn Majah Book 16, Hadith 40 Next Hadith → “The Messenger of Allah (ﷺ) forbade selling surplus water.”

Sunan Ibn Majah Book 16, Hadith 42