Bede

"A muddied spring, and a corrupt fountain," etc. The mouth and tongue of the just are the spring and fountain of life, which meditates wisdom and speaks judgment. And if it happens that this is overcome by the devil and brought to a fall, then rightly it is called a muddied spring trodden down by the adversary, and a corrupt fountain. For it often happens that those who shone with greater knowledge, in the end, wishing to be wiser than is allowed to human frailty, fall into the pit of folly. Hence it is added...

Commentary on Proverbs ↗