Romans 11:33-36:

O the depth of the riches and wisdom and knowledge of God! How unsearchable are his judgements and how inscrutable his ways!
‘For who has known the mind of the Lord?
Or who has been his counsellor?’
‘Or who has given a gift to him,
to receive a gift in return?’
For from him and through him and to him are all things. To him be the glory for ever. Amen.

From John Milbank, “Can a Gift Be Given? Prolegomena To a Future Trinitarian Metaphysic,” Modern Theology 11 (January 1995): 135-136:

One can explicate the coincidence of absolute gratuity with absolute exchange in the following manner. In the usual situation of gift giving, the gift must pass across a ‘neutral’ territory, belonging neither to donor nor donee. Although the gift is intended to pass through this terrain, its neutrality nevertheless helps to secure the freedom of the gift, since if the gift is refused it will remain there, abandoned, unless it is returned to the sender or retrieved by him. If this happens, even the minimum degree of exchange, manifest in the ‘return’ made by gratitude, will be thwarted. yet, in the case of the divine gift, none of this applies. For the very reason that it is a gift to no-one, but rather establishes creatures as themselves gifts, the divine gift passes across no neutral abyss, no interval of uncertainty during which one waits, with bated breath, to see if the destiny of a gift will be realised. Instead, divine giving occurs inexorably, and this means that a return is inevitably made, for since the creature’s very being resides in its reception of itself as a gift, the gift is, in itself, the gift of a return–in the specifically human instance of ‘such a heart whose pulse may by Thy praise’. Not of course, a return that God receive as a need, since he is replete (Romans 11:35), but a return that constitutes the creature itself, and which God receives by grace: ‘Not that thou has not still above/Much better tunes than groans can make,/But that these country-aires Thy love/Did take’. The Creature only is, as manifesting the divine glory, as acknowledging its own nullity and reflected brilliance. To be, it entirely honours God, which means it returns to him an unlimited, never paid-back debt. Of course, in the case of free creatures, this return may not be made, but as we know, such non-return is highly paradoxical and does not, as non-return of human gifts might, augment the status of free creatures as potential recipients, as people requiring a better honouring and placating. On the contrary, it closes off the possibility of any further reception, whether from God or from other creatures. for the sinful self is left merely with the empty gesture of freedom, and absolute control over its own illusory and contentless stability, and robbed of the freedom to do this or that, which is inseparable from a freedom for this or that, involving receptivity. To refuse Being as a gift is to refuse the condition of all receptivity as such, and turns out to mean a refusal of the gift of Being. In such circumstances, God does indeed continue to give, and it is as if, after all, the divine gift hovers in the desert. However, such a situation is a contradiction for God, only resolved when this refusal itself is manifest as inexorable gift and infinite return. Since human refusal forecloses its ontic status as receptacle, consigning it to nothingness, it cannot for itself receive even its own refusal, which is to say, receive its meaning as utter alienation from God, the source of all that is. Only God himself can receive this refusal, which he does, on the cross, so manifesting the refusal as, after all, the reception of a gift. Here, however, infinite return is realized as perfect return, God’s return of himself to himself, and it is disclosed to us that the divine created gift, which realizes an inexorable return, is itself grounded in an intra-divine love which is relation and exchange as much as it is gift.

That intra-divine love being, the perichoresis of the Triune life:

God gives his Spirit; this says the New Testament, is the gift, yet it is the relationship between Father and Son in wich the Father, in fully giving himself to the Son also fully consigns himself, as give, to this infinite form, shape or image of his donation (p. 137).

Beautiful.