CHAPTER THREE: SADHANA ADHYAYA
Section 1: Natichiradhikaranam: Topic 5 (Sutra 23)

It takes only a short time for the descent of the soul.
Natichirena viseshat III.1.23 (314)
(The soul passes through the stages of its descent) in a not very long time; on account of the special statement.
Na: not; Atichirena: in a very long time; Viseshat: because of special statement of Sruti.
The discussion on the soul's way of descent is continued. Next arises the question, does the soul in its descent through ether down to rain, stay at each stage for a very long time, or passes through it quickly? The Purvapakshin or the opponent says: 'There being nothing to define the time of his stay, it remains indefinitely long at each stage.' This view is set aside by this Sutra. This Sutra says that the soul passes through them quickly. This is inferred from the circumstance of the text making a special statement.
The Sruti says, 'Having become a cloud he rains down. Then he is born as rice and corn, herbs and trees, sesamum and beans. From thence the escape is beset with many difficulties. For whoever the persons may be that eat the food, and beget offspring, he henceforth becomes like unto them' (Chh. Up. V.10.5).
The soul's journey, through the stages of the ether, the air, the vapour or smoke, the mist, the cloud and the rain, takes a shorter time than his passing through the stages of corn, semen, foetus, which takes a much longer time or hard suffering, as there is the special statement in Sruti, that after its entrance into a corn the escape is beset with much greater difficulty and pain.
The Sruti says "The souls enter into rice" and adds "from thence the escape is beset with more difficulty and pain." There is a hint here that the escape from the previous states or earlier stages is easy and pleasant and attained quickly.
"He who has begun to descend will enter the mother's body (woMB) before a year passes since starting, though wandering through different places" (Naradiya Purana).