In plain words
The poet, to the Lord: O Tirumāl, consort of Śrī: in that battle [of the Bhārata] thronged with armies, when you set the right-whorled conch to your lips so that all were bewildered, and fought [Bhīṣma] with the hand that holds the discus of war, why did you hide with a wheel [your discus] the sun of darting rays that moves across the sky?