When Romeo and Juliet first speak of the possibility of getting married, Juliet asks Romeo at what time she should send a messenger to him to learn of the arrangements he's made for the wedding. He replies, "By the hour of nine" (2.3.182). Later, Juliet sits and wonders why it is taking the Nurse so long to return to her with Romeo's answer. She says to herself:
The clock struck nine when I did send the Nurse.
In half an hour she promised to return. (2.5.1-2)
Despite the Nurse's promise to return quickly, she has been gone for "three long hours," and Juliet is becoming incredibly impatient to learn what her future will be with Romeo (2.5.11). Juliet laments that her Nurse is so old and slow when she, herself, is so anxious and in need of some speed. Juliet wants to know if Romeo has made arrangements for their marriage, and she does not want to wait any longer.