This is a quote by Elizabeth Proctor.
It is an important quote from The Crucible (1953) by Arthur Miller, a play that explores the story of the Salem witch trials in Massachussets in 1692.
In the play, Elizabeth Proctor is accused of witchcraft by Abigail Williams, her husband's mistress. In that way, the quote is from Elizabeth to John. In this excerpt of the play, she is talking about Abigail, who apparently wants to take Elizabeth's place. Therefore, Elizabeth uses these words to explain her husband that his mistress accuses her of witchcraft because she is motivated by jealously.