Likewise we see that a child has legs but he cannot walk. What is meant by saying that Hod-Yesod-Malchut were not entirely purified during Pregnancy is that these Sefirot were the most ready to become flawed and severely darkened through men’s deeds, as explained in various places in connection with the verse “faint all the day” (Lamentations 1:13), where the letters of the Hebrew word for “faint”, דוה, DaVaH, spell out the word HOD backwards.
Thus we see that this world has also already emerged from desolation in the sense that it has been created and is no longer “desolation and void”. It is just that its “legs” have not been repaired and therefore it has no support and totters time after time. And the sages said, “Because of the nettle the cabbage is hit” (Bava Kama 92a) – which alludes to the way Netzach too becomes darkened because of the flaw in Hod. Thus the various flaws that exist now in the world all cause a flaw in Hod and darken Netzach. The legs exist – the Torah and commandments exist – but they cannot go – there is no strength in them.