17 What He was promising them was a certain feeding and abundant fullness of the Holy Spirit: but the woman did not yet understand; and not understanding, how did she answer? “The woman says unto Him, Sir, give me this water, that I thirst not, neither come hither to draw.” Want forced her to labor, and her weakness was pleading against the toil. Would that she heard the invitation, “Come unto me, all you that labor and are heavy laden, and I will refresh you!” This is, in fact, what Jesus was saying to her, that she might no longer labor: but she did not yet understand.
Source: Tractates on the Gospel of John (New Advent)