Grading: Its chain is "sahih"
Note / Clarification: Ibn Wahb is Abd Allah al-Misri, Ibn Jurayj is al-Makki, and Abu al-Zubayr is Muhammad bin Muslim.

Reference / Source: In Sahih Muslim (1530), it is narrated from Ibn al-Sarh through this same chain of Ibn Wahb; Imam al-Hakim's including it in al-Mustadrak is an oversight (dhuhul) on his part.

Reference / Source: Muslim and al-Nasa'i also narrated it through two other routes from Ibn Jurayj.

Reference / Source: Al-Nasa'i (6094) narrated it with the chain Hajjaj bin Muhammad, from Ibn Jurayj, in these words: the Prophet (peace and blessings be upon him) said: "A heap of food is not to be sold for a heap of food, nor a heap of food for a specified measure (kayl) of food"
Juristic point: Imam al-Nawawi says in "Sharh Muslim": This is an explicit statement that selling dates for dates is unlawful until equality is known with certainty
Principle of jurisprudence: The scholars say that in this chapter "not knowing that there is equality" is exactly like "there actually being inequality" (al-jahl bi-l-mumathalah ka-haqiqat al-mufadalah), because the Prophet (peace and blessings be upon him) laid down the condition "like for like", and equality cannot be ascertained where there is ignorance; the same ruling applies to wheat, barley and other riba-bearing commodities.

Note / Clarification: Al-Azhari says in "al-Zahir" (p. 140): "al-subrah" is a heap of grain that has been gathered by pouring it one part over another.