Variants:
No oaths, no seals, no official mummeries were used; the treaty was ratified on both sides with a yea, yea — the only one, says Voltaire, that the world has known, never sworn to and never broken.
As quoted in William Penn : An Historical Biography (1851) by William Hepworth Dixon
William Penn began by making a league with the Americans, his neighbors. It is the only one between those natives and the Christians which was never sworn to, and the only one that was never broken.
As quoted in American Pioneers (1905), by William Augustus Mowry and Blanche Swett Mowry, p. 80
It was the only treaty made by the settlers with the Indians that was never sworn to, and the only one that was never broken.
As quoted in A History of the American Peace Movement (2008) by Charles F. Howlett, and Robbie Lieberman, p. 33
The History of the Quakers (1762)