Indeed, that's the trouble with ethics; it thinks it is distinct from other such topics.

I don't see that ethical statements must be justified in any distinct from other statements. They are just statements. — Banno

So, can any knowledge about ethics can be derived from ethical acts?

There are justified true beliefs after all.

Not clear what you are asking.

So, we know about what is ethical to do, because we do it in ethical acts.

Can thus we write about what is ethical?

we know about what is ethical to do, because we do it in ethical acts. — Question

Change "because" to "and".

We can write about it. But what is important is that we act.

We can write about it. But what is important is that we act. — Banno

But, Wittgenstein!

He said we must be silent about such things.

He said we must be silent about such things. — Question

Which things?

Evaluating the validity of ethical propositions of course comparatively to the sum total of people in the state of affairs of the world.

Indeed, we do evaluate moral propositions. And in the end, it is quite fine to say "I am just certain that it is so; there is no justification."

And here there can be silence.

I am just certain that it is so; there is no justification. — Banno

So, who ought have the final word on the matter? The lawyers, judge, or jury?

He said we must be silent about such things — Question

There are certain things which the Tractatus says we should keep silent about. But I think, as you know from other exchanges, that the Tractatus is not the 'template' for everything Wittgenstein thought: it's the starting point of a man in his twenties who later saw things more broadly, especially in terms of how we use language and what the grammar of philosophical enquiry is. I've just been reading 'Culture and Value' which is a piecemeal, illuminating summary of other remarks by Wittgenstein about, well, matters of culture and value.

He did talk about Ethics. Famously he's said to have thought it was on a par with Aesthetics. He thought that Ethics-talk involved stepping out of the natural into the Supernatural, and therefore our language renders it nonsense - but nonsense which is attempting to express profound meaning, only our language fails us.

Here's a link to the 1929 lecture on Ethics, it's hard to read in this format, oddly enough it's one of the few things I've found easier to read on a phone than on a pc.

That's just asking "Who do you trust?"