Rostam's Khanjar Finds His Son

From B8.21, The Tragedy of Sohrab. It illustrates B8.21.3–12:

B8.21.3
They closed in wrestling, belt to belt they strained,Each testing what the other’s strength retained.
B8.21.4
Sohrab’s strength seemed fettered in the fight,As though high heaven had bound his arms outright.
B8.21.5
Then Rostam, troubled, seized him by the neck,The warlike nahang, holding him in check.
B8.21.6
The gallant youth, whose time had reached its end,Felt strength depart and could no more contend.
B8.21.7
Then like a lion striking down its prey,Rostam dashed Sohrab upon earth that day.
B8.21.8
He knew the youth would rise if left alive,And drew his khanjar lest he should revive.
B8.21.9
He struck and opened wide the fallen breast;By that dark blow, fate’s sentence stood expressed.
B8.21.10
Who thirsts for blood and stains the water-blue bladeShall find that Time has thirst for him repaid,
B8.21.11
And every hair upon his body thenShall turn into a khanjar’s point again.
B8.21.12
Sohrab writhed and breathed a bitter sigh,Then left all thought of good and ill to die.