Observe the Scriptural text: "And Abraham took another wife, and her name was Keturah" (Gen. xxv, 1). Herein is an allusion to the soul which after death comes to earth to be built up as before. Observe that of the body it is written: "And it pleased the Lord to crush him by disease; to see if his soul would offer itself in restitution, that he might see his seed, and prolong his days, and that the purpose of the Lord might prosper by his hand." (Is. LIII, 10). That is to say, if the soul desires to be rehabilitated then he must see seed, for the soul hovers round about and is ready to enter the seed of procreation, and thus "he will prolong his days, and the purpose of the Lord", namely the Torah, "will prosper in his hand". For although a man labours in the Torah day and night, yet if his source remains fruitless, he will find no place by which to enter within the Heavenly curtain.