E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Kissing the Popes Toe.
Matthew of Westminster says, it was customary formerly to kiss the hand of his Holiness; but that a certain woman, in the eighth century, not only kissed the Popes hand, but squeezed it. The Church magnate, seeing the danger to which he was exposed, cut off his hand, and was compelled in future to offer his foot, a custom which has continued to the present hour.