Gregory the Great — on 2Tim 4:2 (The Book of Pastoral Rule, Part 2, Chapter 4)

“Rulers ought also to guard with anxious thought not only against saying in any way what is wrong, but against uttering even what is right overmuch and inordinately; since the good effect of things spoken is often lost, when enfeebled to the hearts of hearers by the incautious importunity of loquacity; and this same loquacity, which knows not how to serve for the profit of the hearers, also defiles the speaker. Hence Paul also, in admonishing his disciple to be instant in preaching, when he says, I charge thee before God and Christ Jesus, Who shall judge the quick and the dead by His appearing and His kingdom, preach the word, be instant opportunely, importunely, being about to say importunely, premises opportunely, because in truth importunity mars itself to the mind of the hearer by its own very cheapness, if it knows not how to observe opportunity.”