Luke 2:22

And when the days of her purification— As Jesus was circumcised, though perfectly free from sin; so his mother submitted to thepurifications prescribed by the law, notwithstanding she was free from the pollutions common in other births. It was evident, indeed, that she was a mother,—but her miraculous conception was not generally known. Because the law required that the child should be presented in the temple at the end of forty days fromhis birth, and that the usual offering should be made, our Lord's parents would therefore find it more convenient to go up with him from Bethlehem, where he was born, at the distance of sixty miles only, than after Mary's recovery to carry him first to Nazareth, which was a great way from Jerusalem: so that we may suppose reasonably enough, that they continued in Bethlehem all the days of the purification; and that from Bethlehem they went straightway to Jerusalem.