Wonders will never cease
Definition 1 of 1
Pro Tip 1/3Colloquial Usage
This phrase is often used informally to express amazement at something unlikely or unexpected. 
He volunteered to do the dishes — wonders will never cease!
Pro Tip 2/3Sarcasm Potential
Can be used sarcastically to suggest that something is not actually impressive. 
So you finally learned to use the printer—wonders will never cease.
Pro Tip 3/3Cultural Nuance
Understanding cultural context is key as the phrase may confuse non-native speakers who take it literally. 
She made a salad without avocado—wonders will never cease!