Manuchehr Fears Zahhak's Seed

From A8.11, Manuchehr Hears of Zal and Rudabeh. It illustrates A8.11.3–14:

A8.11.3
Before the throne the matter was laid bare,The Mobadan weighed all with solemn care.
A8.11.4
The Shah then said, “Grim days may rise from this;I see no easy road to lasting bliss.
A8.11.5
From lion’s claw and leopard’s savage hand,By counsel and by war I freed the land.
A8.11.6
Did Fereydoon cleanse earth of Zahhak’s reignThat such a root should rise and spread its bane?
A8.11.7
Shall from that seed, long withered and cast down,A branch arise to threaten throne and crown?
A8.11.8
This love, if left to grow, may yet restoreThe very blood we strove to end before.
A8.11.9
If from this union there should rise an heir,A sharpened sword from sheath would meet the air.
A8.11.10
He stands between two worlds and bears two claims:Half bound to us, half to the Dragon’s names.
A8.11.11
How shall two natures so opposed endure?Can poison ever mingle with its cure?
A8.11.12
If toward his mother’s side he bends his will,Corrupting words may then his judgment fill;
A8.11.13
He may fill Iran’s cities full of woe,And crown and treasure to his keeping go.
A8.11.14
Now give me counsel; tell me what you know:What course will guard the realm from overthrow?”