tathā kāśī-pateḥ kāyāc
chira utkṛtya patribhiḥ
nyapātayat kāśī-puryāḿ
padma-kośam ivānilaḥ
tatha -- similarly; kasi-pateh -- of the King of Kasi; kayat -- from his body; sirah -- the head; utkritya -- severing; patribhih -- with His arrows; nyapatayat -- He sent it flying; kasi-puryam -- into the city of Kasi; padma -- of a lotus; kosam -- the flower cup; iva -- as; anilah -- the wind.
Srila Visvanatha Cakravarti explains why Krishna threw Kasiraja's head into the city: "As he went off to battle, the King of Kasi had promised the citizens: 'My dear residents of Kasi, today I will bring the enemy's head into the midst of the city. Have no doubt of this.' The King's sinful queens had also boasted to their maids-in-waiting: 'Today our master will certainly bring the head of the Lord of Dvaraka.' Therefore the Supreme Lord threw the King's head into the city to astonish the inhabitants."