Rashi on the Former Prophets

Was rare. Was withheld, as in, "and a man of understanding speaks sparingly ]יֲקר[", meaning that who speaks sparingly is an understanding man.
Prophetic vision was not widespread. Prophecy was not revealed.נִפְרָץ is an expression similar to, "and you shall spread [וּפָרַצְתָּ] westward and eastward.

And Shmuel was lying. In his place, in the court of the Levites who watch in the Temple. According to Targum Yonoson: "And Shmuel was lying in the court of the Levites."
In the Temple of Adonoy. Where the Ark of God was.

Adonoy called. And a voice emanated from the Temple of God, from the Holy of Holies, which called, "Shmuel!" The end of the above verse is connected to the verse that follows. This is what is inferred by the verse, "the Lord thunders wonderously with His voice." Eili was a kohein, and was watching from within, while Shmuel was a Levite and lying without. Yet, the voice [of 'ה] jumped over Eili to Shmuel.

[Shmuel] had not yet known Adonoy. He had not yet recognized the nature of the prophetic voice. Every time the word 'טֶרֶם' appears in Scripture, it means 'not yet,' as rendered by the Targum 'עַד לָא' [not yet]. It does not mean 'before.' This verse proves it. And another [proof of this] is the verse כִּי טֶרֶם תִּירְאוּן which is rendered as "that you do not yet fear," is a more explicit verse proving this. Also, וְכֹל שִֹיחַ הַשָֹּדֶה טֶרֶם יִהְיֶה בָאָרֶץ ["all plants of the field were not yet on the earth"].

And Shmuel said, "Speak." He did not mention the Name of the Deity as Eili had commanded him, because he said [to himself], 'Perhaps it is another voice.'

To do something. This refers to the capture of the Ark by the Philistines.
Will ring. An expression similar to [צִלְצָלִים], cymbals, tintiner, in O. F.

I will begin to destroy. On that day, My decree upon Eili's family will begin, for Chofni and Pinchas shall die, and from then on, I shall finish my decree and complete it upon them from generation to generation, and cause them to die as young men at the age of eighteen years.
I will begin to destroy. Commencant e espleiant, in O. F.

That his sons were blaspheming themselves. It should properly state, 'blaspheming Me' but Scripture euphemized.
Blaspheming. Meaning, acting irreverantly, and similarly, every curse [קְלָלָה] is an expression of irreverence and disgrace.
He did not censure. I.e., he did not darken [כהה] their faces by removing them from their high positions.

Such shall [God] do to you. Like that very curse, that you shall not have worthy children. And that curse actually befell him even though he did tell him. And did not withhold. From here [the Sages concluded]: A curse of a wise man, even though pronounced on condition, will be realized.

He is Adonoy. He is the Master and everything is His.

For Adonoy revealed Himself to Shmuel. Because Scripture stated above, "The word of Adonoy was rare in those days," it states here that from now on, for Shmuel's sake, He revealed Himself repeatedly.