Final answer:
The phrase 'for unto us a child is born' is from the Bible and has been performed in various religious and musical contexts. It is often associated with Handel's 'Messiah'.
Step-by-step explanation:
The phrase 'for unto us a child is born' is from the Bible, specifically from the book of Isaiah in the Old Testament. It is part of a prophecy about the birth of a special child who would bring peace and prosperity. The exact time and place when this phrase was first performed is not known, as it is part of a religious text that has been recited and performed for thousands of years. However, it is often associated with performances of Handel's 'Messiah' Oratorio, which features this phrase prominently.