hatvā - having killed; kaṁsam - Kaṁsa; raṅga - the arena; madhye - within; pratīpam - the enemy; sarva-sātvatām - of all the Yadus; yat - what; āha - He spoke; vaḥ - to you; samāgatya - by coming back; kṛṣṇaḥ - Kṛṣṇa; satyam - true; karoti - will make; tat - that.

Having killed Kaṁsa, the enemy of all the Yadus, in the wrestling arena, Kṛṣṇa will now surely fulfill His promise to you by coming back.