How many times must a prophet be tested?

Question

Rambam in his Introduction to his Commentary on the Mishna writes:

"...And when the one prophesying is fit for prophecy, according to that which is appropriate, we say to him, "Prove [yourself] to us with predictions and tell us things from among that which the Holy One, blessed be He, has taught you." And he tells and promises [their truth]. And if all of his predictions are substantiated, then we know that all of his prophecies are true. But if he lies about it, or even if one of his words fails – and even if it is a small thing – we know that he is a false prophet...And we should not believe him and say that his prophecy is true when one or two of his proofs are realized, but [rather] his [status] should be contingent until his true signs be many – 'like all that he spoke in the name of the Lord' – one time after another..."

And in Hilchot Yesodei Hatorah 10:1-2, 5 writes:

"...But it shall be said unto him: "If thou be a prophet, fortell things which are to come to pass". If he, indeed, foretells, we wait to see whether his words will come to pass or whether they will not come to pass, when, if even a minute detail be wanting it is certain that he is a false prophet. But if all of his words come to pass, he must be in our eyes trustworthy. The examination must be continued many times; if all of his words be found true, lo, this is a true prophet...A prophet whose prophecy had already been proclaimed, and whose words were believed time after time, or if another prophet gave testimony concerning him, and he continued to follow the paths of prophecy, must not be looked upon with suspicious thoughts, or question the truth of his prophecy. And it is forbidden to test him more than necessary, or go on testing him forever..."

My question therefore is, how many times must an aspiring prophet be tested? Is there a set numerical minimum of tests that must be completed? The Rambam writes "many", but what does that mean?

Answer 1

R. Abraham de Boton writes in Lechem Mishneh to the cited halacha from Mishneh Torah that you test him until the truth is verified, but anything beyond that is forbidden:

כלומר עד שיתאמת אבל לא יותר מדאי כדכתב לקמן דאיכא איסורא דלא תנסו וכו

According to this there is apparently no set number of tests; it is however many it takes to establish the truth.

R. Elazar Ben Shmuel Shmelka Rokeach writes as follows in Arba'ah Turei Even on the cited halacha from Mishneh Torah:

ולכאורה נראה דהיינו שלשה פעמים כמו שדרשו חז"ל ימים רבים ימים שנים רבים שלשה כן כאן פעמים שנים הרבה שלשה ובתלתא זימני דבתלתא זימני הוי חזקה לכ"ע וא"כ הוא מוחזק לנביא ואינו רשאי לנסותו כלל וראיה לדבר ממשה רבינו ז"ל שבתחילת שליחותו למצרים נתן לו הקב"ה ג' אותות שיעשה בפני ישראל

And it would seemingly appear that this is three times, as the Sages of blessed memory have expounded [the words] "many days": "days" – two, "many" – three. So too here, "times" – two, "many" – three. And on three occasions, for with three occasions there is a chazakah according to all [opinions], and if so he is established as a prophet and it is not permitted to [further] test him at all. And a proof to this is from Moses our teacher of blessed memory, for in the beginning of his mission to Egypt The Holy One Blessed Be He gave him three signs to do before Israel.

R. Menachem Korokovsky in Avodat Hamelech on the cited halacha from Mishneh Torah seems to say that the amount of tests required is unclear:

וצ"ב לדעת השיעור לזה

Answer 2

The Torah provides the tests for prophets, to determine whether they speak with the authorization of HaShem. The tests contain only two parts.

The first is whether the prophet calls his hearers to follow other gods. D'varim (Deuteronomy) 13:2-4

2 If there arise in the midst of thee a prophet, or a dreamer of dreams--and he give thee a sign or a wonder,

3 and the sign or the wonder come to pass, whereof he spoke unto thee--saying: 'Let us go after other gods, which thou hast not known, and let us serve them';

4 thou shalt not hearken unto the words of that prophet, or unto that dreamer of dreams; for HaShem your G-d putteth you to proof, to know whether ye do love HaShem your G-d with all your heart and with all your soul.

It could be argued (and probably has!) that this is moreso a test for the hearers than for the prophet himself, though a prophet that failed this part was to be executed, per verse 6.

And the second, which seems the main thrust of this question, is whether anything fails that the prophet states. D'varim (Deuteronomy) 18:20-22

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 HaShem hath not spoken?'

22 When a prophet speaketh in the name of HaShem, if the thing follow not, nor come to pass, that is the thing which HaShem hath not spoken; the prophet hath spoken it presumptuously, thou shalt not be afraid of him.

This "presumption" test itself has two parts: (1) "if the thing follow not," and (2) "nor come to pass." The second seems easy enough, but we'll come back to it. "Follow" here could mean either (a) "to come behind" or (b) "to be a logical conclusion of {something else}." The former (a) would cause the second part (2) to simply be a reiteration, while the latter (b) would suggest a separate aspect of the test: "Does this prophecy match other established teachings from G-d (perhaps especially concerning His character)?"

Coming back to the phrase "come to pass," the most probable sticking point, then, might be concerning things that a prophet seemingly loyal to HaShem predicted would occur well after the prophet's death, in which case, the audience for his prophecies -- whether his immediate hearers or later readers (including possibly us!) -- would have to look at the rest of that prophet's prophecies to see whether any of them had failed the tests. So it seems that there's not exactly guidance on the question, "How many should come true?" But rather the question ought to be, "Did any fail?"

It would seem, then, that a prophet's testing is technically continually on-going, as anything the prophet prophesies must be both loyal to HaShem and fit within the parameters of the rest of established Scripture and verified prophecies, and itself not fail to occur.