Those who said: if he specifies measure and weight, let him measure

It is narrated from al-Hakam that in the time of the Prophet (peace and blessings be upon him) a consignment of food arrived for Sayyiduna Uthman (may Allah be pleased with him), so he (peace and blessings be upon him) said: "Come with us to Sayyiduna Uthman (may Allah be pleased with him) so that we may help him sell the food." He (peace and blessings be upon him) stood at his side, while Sayyiduna Uthman (may Allah be pleased with him) was saying: In this sack there is such and such an amount, and I will sell it for such and such. He (peace and blessings be upon him) said: "When you have named and specified it, then measure it out."

Ibn Sirin said: When the measure and weight have been named and specified, do not sell it onward before measuring it.

Qatadah and al-Hasan (may Allah have mercy on them both) said: When the measure and weight have been named and specified, it should then be measured.

Ibrahim (may Allah have mercy on him) said: When you enter into a salam (advance-payment) sale and specify the measure, then do not take it by estimate.

Al-Sha'bi (may Allah have mercy on him) said: When you buy food in its wasqs, that is, when you buy it by measure, then measure it.