Page "Jury trial" Paragraph 15

Although it says and or by the law of the land, this in no manner can be interpreted as if it were enough to have a positive law, made by the king, to be able to proceed legally against a citizen.

The law of the land was the consuetudinary law, based on the customs and consent of John ’ s subjects, and since they did not have Parliament in those times, this meant that neither the king nor the barons could make a law without the consent of the people.