Tafsir of Al-Qasas 28:74

(And the Day He will call to them) is in the accusative case as an object of an implied ‘Adhkur’ (Remember).

(And He will say, "Where are My partners whom you used to claim?") This is a reproach following a reproach, to signal that nothing is more conducive to the wrath of Allah the Exalted than associating partners with Him (shirk), just as nothing is more conducive to His pleasure than His Oneness (Tawhid).

Alternatively, the first [reproach] is to demonstrate the corruption of their opinion, as indicated by His saying there: (The word became justified against them). The latter is to demonstrate that their polytheism was not based on any evidence, but rather on mere caprice, as indicated by His saying afterward: (Bring your proof).

Or, the first is to summon the partners to show their unfitness, due to His saying thereafter: (Call your partners, and they will call upon them). This serves to make them regret that they were never upon anything in their acts of idolatry; do you not see His saying: (And lost from them is what they used to invent).