The barren womb; for as the Israelitish women did generally and vehemently desire many children, for divers reasons elsewhere mentioned; so those who were barren amongst them were most eager in those desires, as we see in Rachel, Gen_30:1, and as in all other cases persons most prize and thirst after those good things which they want.
The earth; which when it is dry thirsts for rain, and in a little time sucks up great quantities of water, and gapes for more.
The fire; which continually burns as long as there is any combustible matter left for it.