What is a quotation from Macbeth which describes the witches' relationship to each other?

At the beginning of Act 1, scene 3, the scene in which the Weird Sisters confront Macbeth and Banquo with their respective prophecies as the two nobles return from the battlefield, the witches first meet up with one another and discuss what they've been doing since they last met (in Act 1, scene 1). The first witch asks, "Where has thou been, sister?" to which the second witch replies, "Killing swine" (1.1.1, 1.1.2). The third witch then asks the first witch, "Sister, where thou?" (1.3.3) These lines would indicate that the three witches are, in fact, sisters. Further, they seem to have a rather supportive relationship; when the first witch says that she's going to sail to Aleppo and seek revenge on the husband of a woman who wouldn't share her food, the second witch says, "I'll give thee a wind," to which the first witch replies, "Th' art kind" (1.3.12, 1.3.13). So, the three witches are sisters who have much in common and help one another with their vindictive pursuits.