St. Thomas Aquinas on Changing the Traditions

 "It is absurd, and a detestable shame, that we should suffer those traditions to be changed which we have received from the fathers of old."

St. Thomas Aquinas, Summa Theologiae, 1a2ae.97.2 sed contra; 

From Gratian, Decreta, Distinction 12, ch. 5, quoting from a letter of Pope St. Nicholas I to Abp. Hincmar:

"It is a ridiculous and abominable disgrace that in our times we permit the holy Church of God to be slandered and that we suffer the traditions we have received from the fathers of ancient times to be infringed at will by those wandering from the truth."

Source: Gratian, The Treatise on Laws, trans. Augustine Thompson, With the Ordinary Gloss, trans. James Gordley (Washington, DC: Catholic University Press, 1993), 44.

h/t Fr. Thomas Crean, OP. https://twitter.com/crean_fr/status/1530922903054733315