Thou art my King, O God: command deliverances for Jacob.
Thou art my King, O God - literally, 'Thou art He (that is) my King.' Thou art the One that pre-eminently hast kingly authority and irresistible might, and so art able to save us (Psalms 74:12).
Command deliverances - salvations. A command from thee is enough instantly to ensure manifold salvation, according to the several exigencies (Psalms 147:15; Psalms 107:20; Matthew 8:8-9).