That the Prophet (ﷺ) said: "Whoever buys food, then he is not to sell it until he takes possession of it." Ibn 'Abbas said: "All things are considered the same (in this regard)."

There are narrations on this topic from Jabir, Ibn 'Umar, and Abu Hurairah.

The Hadith of Ibn 'Abbas is a Hasan Sahih Hadith.
Jami` at-Tirmidhi Book 14, Hadith 93
← Previous Hadith "The Messenger of Allah (ﷺ) prohibited Al-Muhaqalah, Al-Muzabanah, Al-Mukhabarah, and making an exception (in a sale) unless it is made known."

This Hadith is Hasan Sahih, Gharib from this route as narration of Yunus bin 'Ubaid, from 'Ata, from Jabir.

Jami` at-Tirmidhi Book 14, Hadith 92 Next Hadith → That the Messenger of Allah (ﷺ) said: "None of you is to sell over the sale of others, nor to propose over the proposal of others."

There are narration on this topic from Abu Hurairah and Samurah.

The Hadith of Ibn 'Umar is a Hasan Sahih Hadith.

And it has been reported from the Prophet (ﷺ) that he said: "Do not haggle in competition with your brother's haggling." And the meaning of sale in this Hadith of the Prophet (ﷺ), according to some of the people of knowledge is to haggle.

Jami` at-Tirmidhi Book 14, Hadith 94