“Aaron’s sons Nadav and Avihu took their censers, put fire in them and added incense; and they offered unauthorised fire before the Lord, which [God] had not instructed them [to offer]. Fire came out from the Presence of the Lord and consumed them, and they died before the Lord”.

Lev. 10:1-2

Many explanations were given by the Sages and later commentators as to what Nadav and Avihu’s sin actually was. But the simplest answer, given by the Torah itself here and elsewhere (Num. 3:4, Num. 26:61), is that they acted on their own initiative. They did what they had not been commanded. They acted spontaneously, perhaps out of sheer enthusiasm in the mood of the moment, offering “unauthorised fire”. Evidently it is dangerous to act spontaneously in matters of the spirit.

But is it? Moses acted spontaneously in far more fraught circumstances when he shattered the Tablets of Stone upon seeing the Israelites cavorting around the Golden Calf. The tablets – hewn and engraved by God Himself – were perhaps the holiest objects there have ever been. Yet Moses was not punished for his act. The Sages said that though he acted of his own accord without first consulting God, God assented to this act. Rashi refers to this moment in his very last comment on the Torah, whose last verse (Deut. 34:12) speaks about “all the strong hand, and all the great awe, which Moses performed before the eyes of all Israel”:

This refers to when Moses] took the liberty of shattering the tablets before their eyes, as it is said, “I shattered them before your eyes.” The Holy One, Blessed be He, consented to his opinion, as it is said, “which you shattered” – ‘More power to you for shattering them!’

Why then was spontaneity wrong for Nadav and Avihu yet right for Moshe Rabbeinu? The answer is that Nadav and Avihu were Kohanim, Priests. Moses was a Navi, a Prophet. These are two different forms of religious leadership. They involve different tasks, different sensibilities, indeed different approaches to time itself.

The Kohen serves God in a way that never changes over time (except, of course, when the Temple was destroyed and its service, presided over by the Kohanim, came to an end). The Prophet serves God in a way that is constantly changing over time. When people are at ease the Prophet warns of forthcoming catastrophe. When they suffer catastrophe and are in the depths of despair, the Prophet brings consolation and hope.

The words said by the Kohen are always the same. The priestly blessing uses the same words today as it did in the days of Moses and Aaron. But the words used by a Prophet are never the same. As it is noted:

“No two Prophets use the same style.”

Sanhedrin 89a

So for a Prophet spontaneity is of the essence. But for the Kohen engaged in Divine service it is completely out of place.

Why the difference? After all, the Priest and the Prophet were serving the same God. The Torah uses a kind of device we have only recently re-invented in a somewhat different form. Stereophonic sound – sound coming from two different speakers – was developed in the 1930s to give the impression of audible perspective. In the 1950s 3D film was developed to do for sight what stereo had done for sound. From the work of Pierre Broca in the 1860s to today, using MRI and PET scans, neuroscientists have striven to understand how our bicameral brain allows us to respond more intelligently to our environment than would otherwise have been possible. Twin perspectives are needed fully to experience reality.

The twin perspectives of the Priest and Prophet correspond to the twin perspectives on creation represented, respectively, by Genesis 1:1–2:3 (spoken in the priestly voice, with an emphasis on order, structure, divisions and boundaries), and Genesis 2:4–3:24 (spoken in the prophetic voice, with an emphasis on the nuances and dynamics of interpersonal relationships).

Now let us consider one other area in which there was an ongoing argument between structure and spontaneity, namely tefillah, prayer, specifically the Amidah. We know that after the destruction of the Temple, Rabban Gamliel and his court at Yavneh established a standard text for the weekday Amidah, comprising eighteen or later nineteen blessings in a precise order (Mishnah Brachot 4:3).

Not everyone, however, agreed. Rabbi Joshua held that individuals could say an abridged form of the Amidah. According to some interpretations, Rabbi Eliezer was opposed to a fixed text altogether and held that one should, each day, say something new (Talmud Yerushalmi Brachot 4).

It seems that this disagreement is precisely parallel to another one about the source of the daily prayers:

It has been stated: R. Jose, son of R. Hanina said: The prayers were instituted by the Patriarchs. R. Joshua b. Levi says: The prayers were instituted to replace the daily sacrifices.

Brachot 26b

According to R. Jose, son of R. Hanina, Shacharit was established by Abraham, Minchah by Isaac, and Maariv by Jacob. According to R. Joshua b. Levi, Shacharit corresponds to the daily morning sacrifice, and Minchah to the afternoon sacrifice. On the face of it, the disagreement has no practical consequences, but in fact it does.

If the prayers were instituted by the patriarchs, then their origin is prophetic. If they were established to replace the sacrifices, then their provenance is priestly. Priests were forbidden to act spontaneously, but Prophets did so as a matter of course. Someone who saw prayer as priestly would, like Rabban Gamliel, emphasise the importance of a precise text. One who saw it as prophetic would, like Rabbi Eliezer as understood by the Talmud Yerushalmi, value spontaneity and each day try to say something new.

Tradition eventually resolved the matter in a most remarkable way. We say each Amidah twice, once privately and silently in the tradition of the Prophets, then a second time publicly and collectively by the shaliach tzibbur, the “reader’s repetition”, in the tradition of a Priest offering a sacrifice at the Temple. (It is easy to understand why there is no reader’s repetition in the Maariv service: there was no sacrifice at night-time). During the silent Amidah we are permitted to add extra words of our own. During the repetition we are not. That is because Prophets acted spontaneously, but Priests did not.

The tragedy of Nadav and Avihu is that they made the mistake of acting like Prophets when they were, in fact, Priests. But we have inherited both traditions, and wisely so, for without structure, Judaism would have no continuity, but without spontaneity it would have no fresh life. The challenge is to maintain the balance without ever confusing the place of each.