The garden can be watered in four ways.
(taken from The Book of Her Life, Chap 11 ~St. Teresa of Jesus)
You may draw water from a well (which is for us a lot of work).
Or you may get it by means of a water wheel and aqueducts in such a way that it is obtained by turning the crank of the water wheel. (I have drawn it this way sometimes - the method involves less work than the other, and you get more water.)
Or it may flow from a river or stream. (The garden is watered much better by this means because the ground is more fully soaked and there is no need to water so frequently - and much less work for the gardener.)
Or the water may be provided by a great deal of rain. (For the Lord waters the garden without any work on our part- and this way is incomparably better than all the others mentioned.)