wonders (will) never cease

This was not at all expected; how shocking. Said especially of that which is pleasantly surprising, though the phrase is often used humorously, ironically, or sarcastically. The famously defiant and aggressive leader today announced that he wanted to form a close alliance and kinship with his neighbors to the south. Wonders never cease, it seems. Jake actually volunteered to do the dishes after dinner? Wonders will never cease!

Prov. What an amazing thing has happened! (Said when something very surprising happens. Somewhat ironic; can imply that the surprising thing should have happened before, but did not.) Fred: Hi, honey. I cleaned the kitchen for you. Ellen: Wonders never cease! Jill: Did you hear? The company is allowing us to take a holiday tomorrow. Jane: Wonders never cease! Not only was my plane on time, the airline also delivered my luggage safely. Will wonders never cease?

What a surprise, as in He's on time-wonders will never cease. This expression is generally used ironically. [Late 1700s]

That is really surprising. This expression, today usually put ironically and nearly always a response to a statement about something the speaker thinks is unusual, dates from the late eighteenth century. Anthony Price used it in Other Paths to Glory (1974): “Wonders will never cease . . . Early Tudor, practically untouched.” This saying has become so familiar that Ed McBain could abbreviate it: “Would wonders never?” (Hark! 2004).