[Spanish] What triggers the subjunctive in this sentence?

[Jaleel10]

Lo que le estoy diciendo es que puede ser que las gambas no estuvieran a su gusto, lo entiendo. Pero que me diga usted, que en restaurante, que tiene más de 120 años, me diga que yo he servido las gambas duras. Rodrigo, yo por ahí no paso.

My best guess is that it's an omission of ''El hecho de''

Context

[SGP]

Lo que le estoy diciendo es que puede ser que las gambas no estuvieran a su gusto, lo entiendo. Pero que me diga usted, que en restaurante, que tiene más de 120 años, me diga que yo he servido las gambas duras. Rodrigo, yo por ahí no paso.

My best guess is that it's an omission of ''El hecho de''

Sometimes I wouldn't know the full answer, but could be able to at least provide some impulses. (Just as I did in an English thread when mentioning that some sentences are called "tag questions", without myself being able to answer the very question that has been asked.)

So after reading having at least read this post of yours about "diga", there is something I'd like to add.

One should keep in mind that "diga" has multiple uses:

Subjunctive Present for "yo"
Subjunctive Present for "él/ella/usted"
Imperative for "él/ella/usted"

This should be kept in mind regardless of
a) knowing that a specific sentence's context enables all of these possibilities,
b) not knowing whether the context enables all of them or not,
c) or even being able to know that a certain context disables all but one possibility.

But why should the multiple uses of "diga" be kept in mind, especially in the case of c)? Because sometimes (generally speaking), there also can be something like a slip of the tongue, leading to that person saying something he/she didn't really intend.

And as for b), it can be helpful, too, to think of whether that person could have used some metaphorical or otherwise not-entirely-that-common way of speech.

[Jaleel10]

The multiple usage thing is fine. I just want to know how it's triggered.

Like in the first sentence

Lo que le estoy diciendo es que puede ser que las gambas no estuvieran a su gusto, lo entiendo

A clear subjunctive trigger.

But the next sentence doesn't have any. I know that in phrases like:

(Espero) Que tengas un lindo día - I hope you have a nice day
(Deja) Que pase - Let him through

It's normal to omit the trigger so I was wondering what the next sentence's trigger is.

[Ogrim]

The use of subjunctive derives from the main clause, in your example "yo por ahí no paso". You could rewrite the sentence to something like "Yo no acepto que me diga que yo he servido gambas duras", in which case the subjunctive follows from "yo no acepto que", and "yo por ahí no paso" has more or less the same meaning as "no acepto". I guess the difficulty in your example is that the subordinate clause comes before the main clause, which makes the use of subjunctive less obvious, but the construction *"Yo por ahí no paso que me digas" is impossible.

[Jaleel10]

The use of subjunctive derives from the main clause, in your example "yo por ahí no paso". You could rewrite the sentence to something like "Yo no acepto que me diga que yo he servido gambas duras", in which case the subjunctive follows from "yo no acepto que", and "yo por ahí no paso" has more or less the same meaning as "no acepto". I guess the difficulty in your example is that the subordinate clause comes before the main clause, which makes the use of subjunctive less obvious, but the construction *"Yo por ahí no paso que me digas" is impossible.

Christ, Ogrim. This makes perfect sense
I never would have thought of that in a million years tbh. As always, thanks for your help

Is this something common? It seems pretty scary tbh haha

[SGP]

The multiple usage thing is fine. I just want to know how it's triggered.

Sure, but sometimes I still would reply like this unless knowing that this (possible) puzzle piece wouldn't be required . Also, because this is a public forum, some Question Related Clues may be rather obvious to some readers while the very same couldn't be said about some others.

(By the way, I recently started to practice thinking in Spanish some more, and it seems that the words could start to flow rather soon. Until now, I wasn't able to write too much in it without several Looking Up Some Words Writing Flow Pauses. So maybe one day I, too, could be of some more help, related to this Very Beloved Language to me, than just providing some possible clues.)

I guess the difficulty in your example is that the subordinate clause comes before the main clause, which makes the use of subjunctive less obvious, but the construction *"Yo por ahí no paso que me digas" is impossible.

Is this something common? It seems pretty scary tbh haha

Someone else is also wondering about it just a little bit.
As for the subordinate clause coming before the main one, is it something that can happen very often, but natives are still able to recognize?
Or could it maybe be something less-than-entirely-obvious even to some natives?

[nooj]

Is this something common? It seems pretty scary tbh haha

Es muy corriente que una oración subordinada va antepuesta a la oración principal.

P.ej. Que me digas eso me parece aberrante.

[Jaleel10]

Es muy corriente que una oración subordinada va antepuesta a la oración principal.

P.ej. Que me digas eso me parece aberrante.

Te lo agradezco