Imam Baqir (peace be upon him): Whenever Allah the Mighty and Majestic wills to create a drop of fluid — one from which He had taken the covenant in the loins of Adam, or one concerning which bada (a change in the divine decree) occurs for Him — and to place it in the womb of a woman, He rouses the man for intercourse and reveals to the womb: "Open your door, that My creation and My binding decree and destiny may enter you." So the womb opens its door and the drop reaches the womb. It remains there for forty days, then becomes a clot of blood for forty days, then becomes a mudgha (a chewed lump of flesh) for forty days, and then becomes flesh through which interwoven veins run. Then Allah sends two creating angels, and those two create in the wombs whatever Allah wills. They enter the woman's belly through her mouth and from there reach the womb. The foetus already has within it the ancient spirit that has been transferred through the loins of men and the wombs of women. The two angels then breathe into the body of the foetus the spirit of life and continuance, and by the permission of Allah the Exalted they form for it hearing, sight, and all limbs and inner organs. Then Allah reveals to these two angels: "Write upon him My decree and destiny and My binding command, and stipulate for Me bada (the power to alter) in whatever you write." The two say: "O Lord, what shall we write?" Allah reveals to them to lift up their heads towards the head of the mother. They lift up their heads, and when the Tablet touches the mother's forehead, the two angels see in that Tablet the child's form, its adornment, the length of its life, its covenant, its wretchedness or felicity, and everything that pertains to it. Then one of the two dictates these things to the other and he writes them, and they also write this condition: in all these matters bada belongs to Allah. Then they seal the writing and place it upon the forehead of the foetus and stand the child upright in the mother's belly. The Imam said: "And it may happen that the foetus rebels and turns over, and this only occurs in the case of the insolent and the rebellious." When the time of the child's birth arrives — whether nine full months or less — Allah the Mighty and Majestic reveals to the womb: "Open your door, so that My creation may pass out to My earth and My command concerning him may be carried out; the time of his coming forth has arrived." The womb opens the way for the foetus, and Allah sends an angel called Zajir (the Driver) who drives the child in such a way that the child takes fright and is turned upside down, so that its feet come above its head and its head comes at the lower part of the belly, in order that the delivery may be made easy both for the mother and for the child. If the birth and the child's coming forth prove difficult, the angel Zajir startles the child once again, and the child takes fright and falls to the ground crying and terrified.