In whichever mold he becomes pure and knows his Creator and the entirety of Truth from all its aspects, and denies falsehood from all its aspects, he is raised to heaven and becomes as we have previously explained.

On the Method of Metamorphosis:

As for the transfer (Naqla) from one state to another—from human molds to human [molds], and from the molds of transmigration to the molds of transmigration, one from another—it occurs in various ways:

One of them: That which is transferred into the wombs and emerges through birth, among the believers, the dissenters, and the deniers.

As for the believer: If it is willed for him to emerge into the humanity (al-Nasutiyya) within the nations, from one mold to another and from non-existence to existence, he is created from the sperm-drop (Nutfa) that settles in the womb.

[10] And the Knower (al-'Alim)—exalted is His might—was asked about that, and he said: "He remains as a white sperm-drop for twenty days, then a clinging clot ('Alaqa) for twenty days, then fresh blood for twenty days, then he becomes a chewed-like lump (Mudgha) for twenty days—resembling a piece of meat—then he becomes bone for twenty days, then he is clothed in flesh for twenty days, then he is delineated into a form for twenty days.