There is an entire theology hidden in that little word.

Amen means affirmation, faithfulness, truth.

The blessing descends in articulated form.

Amen rises from the receiver.

It says:

I received.

I consent.

I join.

I make this true within my side of the relationship.

This is not power seized from the giver.

It is covenant completed by the receiver.

Sinai itself has this structure.

Hashem speaks.

Israel answers:

There is the downward word.

There is the upward answer.

Torah requires both.

Malchus is the nation saying Amen to existence.