PLEASE I NEED HELP!!!!!! I HAVE TO TYPE A RESPONSE!

Take special note of the last few lines of the “The Collar” by George Herbert:

But as I raved and grew more fierce and wild,
At every word,
Methoughts I heard one calling, Child!
And I replied, My Lord.

How do these lines end the somewhat heavy poem on a more lighthearted note? How does the speaker's tone change over the course of the poem?