The Shah Strikes Ball in Bowl

From C4.2, Kay Khosrow Musters against Afrasiab. It illustrates C4.2.4–8:

C4.2.4
Upon an elephant they set a throneOf turquoise, bright as heaven’s jeweled stone.
C4.2.5
The world grew dark as indigo that day;The Shah sat crowned above the great array.
C4.2.6
From plain and court the shouts of triumph rose;No room remained for movement or repose.
C4.2.7
Upon his elephant, the Shah of mightStruck ball in bowl to summon men to fight.
C4.2.8
Then round his waist he drew the warrior’s band,And girt himself for battle and command.