Wouldn't that be הִילֵּל?

Indeed, הִילֵּל is what's listed in Jastrow, not הֵילֵל

Yes, but the citation from Isaiah is referring to the rising of the "morning star", the planet Venus. The concept of the heavenly bodies praising while they are visible is repeated often in the Torah.

Sure but to say this verb is the pi'el form of h.l.l. is incorrect. So is saying that Jastrow includes this verb form.

The concept of speech within the Torah is the idea of communicating what is hidden within oneself to another. It becomes external and revealed. The "speech" of the stars and planets is their reflected light or radiation. When they shine to us, it is their praise, like is expressed in the "הכל יודוך" prayer and the "אל אדון" prayer said on Shabbat morning.

@Daniel look at the earlier page citation in Jastrow. He makes the Binyan association. If memory serves, I think he brought it from the Aruch. That is a very authoritative source for word meaning.

Once again, I'm not disagreeing necessarily with your translation. I'm disagreeing with your statements about Hebrew grammar. The citation in Jastrow is for הִילֵּל not הֵילֵל

Never used this function. The word usage in Isaiah is as a noun, not a verb. So I would suggest that the vowelization is not strictly about proper conjugation. Nekudot variations are often an indication of a change of effect or פעולה. Contextually, it would make sense with the meaning. When I say this, I am talking about the kabbalistic effect. You have to remember that this is Navi and Isaiah was the one of the greatest after Moshe.

@YaacovDeane "According to Jastrow on page 366 in the following link it is the Pi'el Binyan of the verb form hollal."

That is from your answer

But on page 366, this spelling does not appear

And now you're saying this word isn't a verb at all (which I agree with)

That sentence is the part I disagree with

The questioner is asking about the word meaning in Isaiah. You agree with that aspect of my answer. If you don't like, or follow what I'm talking about with why the nekudot change, that's fine. I'd love to hear a better and correct explanation that takes into account all the points I've mentioned. But I will emphasize one more time, when dealing with nouns and how they are vowelized, the concepts and rules are very different. It is discussed at great length in many early kabbalistic Seforim.

@YaacovDeane I'm looking at that page right now

It lists the name Hillel

and it references the verb הִלֵּל

which is indeed the Pi'el form of the root h.l.l.

It doesn't mention הֵילֵל at all

so that citation to Jastrow is irrelevant

And הֵילֵל is 100% simply not the Pi'el form of anything

It clearly comes from the root h.l.l.

that much is obvious

But everything that you wrote in your answer is simply wrong.

It's not Pi'el and it's not listed on page 366 of Jastrow

(To respond to me, please type @Daniel so that I get a notification)