Invoking Hashem's Name Without Explicit Divine Sanction


Mouthpiece or Playwright?

Throughout most of the Torah, Moshe plays the role of mediator between Hashem and man.  Hashem speaks and Moshe relays His words or commands to mankind.  On several occasions, however, Moshe speaks in the name of Hashem and invokes Divine authority,1 even though we have no record of Hashem previously communicating the essence of Moshe's content:2

How should all of these cases be understood?  Should we assume that, despite the textual silence, Moshe must nonetheless be operating according to a received Divine directive?  Or, is it possible that, at times, Moshe acts on his own initiative?  How much autonomy does any prophet have, and was Moshe any different than other prophets in this regard?  Is Moshe merely Hashem's mouthpiece, or does he have the authority to make his own decisions and write his own speeches, and even to attribute these to Hashem?6

How Complete a Record?

The flip side of the above issue is the question of what and how much the Torah chooses to record for posterity.  Is there a need to record both Hashem's instructions to Moshe to speak to the nation and Moshe's execution, or can one suffice?  In some instances, both Hashem's command and Moshe's transmission are found in the text.7  In other cases, though, only Hashem's words are mentioned, while Moshe's fulfillment is only assumed.8  The above cases, where just Moshe's speech is recorded, are rare.  Why does the text sometimes employ one method and other times another? If everything is happening at Hashem's behest, why are His words not always recorded? If not, what allows Moshe to speak in His name?

Test of a True Prophet

Devarim 18 discusses laws relating to prophets and the criteria for determining who is a true or false messenger:

(כ) אַךְ הַנָּבִיא אֲשֶׁר יָזִיד לְדַבֵּר דָּבָר בִּשְׁמִי אֵת אֲשֶׁר לֹא צִוִּיתִיו לְדַבֵּר וַאֲשֶׁר יְדַבֵּר בְּשֵׁם אֱלֹהִים אֲחֵרִים וּמֵת הַנָּבִיא הַהוּא. (כא) וְכִי תֹאמַר בִּלְבָבֶךָ אֵיכָה נֵדַע אֶת הַדָּבָר אֲשֶׁר לֹא דִבְּרוֹ י"י. (כב) אֲשֶׁר יְדַבֵּר הַנָּבִיא בְּשֵׁם י"י וְלֹא יִהְיֶה הַדָּבָר וְלֹא יָבֹא הוּא הַדָּבָר אֲשֶׁר לֹא דִבְּרוֹ י"י בְּזָדוֹן דִּבְּרוֹ הַנָּבִיא לֹא תָגוּר מִמֶּנּוּ. 
(20) But the prophet, that shall speak a word presumptuously in My name, which I have not commanded him to speak, or that shall speak in the name of other gods, that same prophet shall die.' (21) And if thou say in thy heart: 'How shall we know the word which the Lord hath not spoken?' (22) When a prophet speaketh in the name of the Lord, if the thing follow not, nor come to pass, that is the thing which the Lord hath not spoken; the prophet hath spoken it presumptuously, thou shalt not be afraid of him.

These verses appear to imply that a prophet is not even allowed to relay speech in Hashem's name absent an explicit command.  If so, is it possible to suggest that Moshe nevertheless did so?  Does this prohibition apply in all scenarios, or might there be certain unique situations where such speech is justified and permitted? 

"Fulfilling the Words of His Prophets"

A contrast between true and false prophets and Hashem's relationship with each appears again in Yeshayahu 44:

(כה) מֵפֵר אֹתוֹת בַּדִּים וְקֹסְמִים יְהוֹלֵל מֵשִׁיב חֲכָמִים אָחוֹר וְדַעְתָּם יְסַכֵּל.  (כו) מֵקִים דְּבַר עַבְדּוֹ וַעֲצַת מַלְאָכָיו יַשְׁלִים הָאֹמֵר לִירוּשָׁלַ‍ִם תּוּשָׁב וּלְעָרֵי יְהוּדָה תִּבָּנֶינָה וְחׇרְבוֹתֶיהָ אֲקוֹמֵם.
(25) That frustrateth the tokens of the imposters, And maketh diviners mad; That turneth wise men backward, And maketh their knowledge foolish; (26) That confirmeth the word of His servant, And performeth the counsel of His messengers; That saith of Jerusalem: 'She shall be inhabited'; And of the cities of Judah: 'They shall be built, And I will raise up the waste places thereof';

In these verses, Hashem promises to fulfill the words of his prophets and messengers, implying that, at times, a prophet might speak without Hashem's prior command, and that nonetheless Hashem will make sure that his declaration comes true.  How does this principle relate to the above examples and to Devarim 18?   Does the autonomy intimated here also permit the prophet to invoke Hashem's name as being the source of his prophecy?