How do we reconcile the prohibition of eating and drinking while standing with the permissibility of doing so while walking?

The questioner : Excuse me, Shaykh, regarding the prohibition of eating and drinking while standing and the permissibility of eating and drinking while walking, Shaykh, how is this? Does it mean that if a person walks, he is able to do it, but if he stands, he is not?

The Shaykh : This is not a way of circumventing the ruling of the Shari'ah, but rather a facilitation for one who is in a hurry. If a person has enough time to sit, he should sit to drink, so that he does not commit a violation of the Prophet (peace be upon him) when he prohibited drinking while standing. As for the one who is in a hurry, that is the one who walks and eats and drinks if he is able to.
The student : Peace be upon you, our Shaykh.

The Shaykh: And upon you peace.

The questioner : Is it permissible for a person to eat and drink while sitting on his side, meaning leaning on his right or left side?

The Shaykh : It is permissible.

The Shaykh : When the merchants were prohibited from selling their goods until they had moved them, it was not known that they had bought them. They had bought them and they became their property, so they were prohibited from selling them until after they had...