What is meant by "wheat for wheat" in the Noble Hadith, and what is the benefit of this exchange?

The aforementioned Hadith is authentically reported from the Prophet (ﷺ) and its content is a matter of consensus. Its benefit lies in fulfilling people's various desires. So, whoever has gold and wants dinars sells the gold for dinars, for example, like for like, hand to hand. Similarly, whoever has one type of wheat and desires another type sells it like for like, hand to hand. This applies to dates and other commodities. The types of wheat are many and varied in terms of ease of grinding and suitability for different meals.