My son Aharon is b'Ezras Hash-m having his Bar Mitzvah on Shabbos Parshas Vayikra this year.

His Dvar Torah is going to be based on Vayikra 1:8 as cited (per the Torah Temima) by Zevachim 62b.

When I learned through this drasha (with Rabbi Greenspan of RBS) he explained that Moshe cut blocks of wood 1 small amah square that fit with a half tefach border within the 1 large amah square Mizbeach.

In reviewing the few lines of the Gemara needed for the drasha I am less clear on how this is explained in the Gemara.

Could I please have a little refresher? The Gemara seems to be saying just that the wood cannot stick out beyond the Mizbeach.

The topic that my son will be discussing is that normally these days when we split firewood they are as we can see at the Temple Institute, which is rectangular, not square. From this Gemara we can we can see that the blocks of wood that Moshe cut are square.

Using the principles of an inscribed square we're going to envision that if there was a tree with a circular cross section with a diameter of 1 small amah this would be suitable and such a tree could be sliced like a cucumber and still fit on the Mizbeach.

Although the long planks for the walls of the Mishkan surely had to be cut the way a saw mill would make lumber, it seems a lot easier to slice a tree trunk to make the blocks as the Gemara describes.

Still Moshe would need to measure the tree diameter with some sort of caliper to be sure that its diameter in the two directions was not larger than a small amah.

We also want to go through some of the math calculations of area of a round block, and also see how a round amah block's area would compare with a square black a small amah per side and the amount of border.

Could we please see more commentary on the Gemara that might touch upon any of these issues?

Also to see if there is any comparison with the words used for example by Avraham when he split wood for the Akeidah.

Chaim Chesler, Providence, RI

Dear Rav Kornfeld and Rav Bloom,

I am not comfortable to discuss matters on any daflist mailing list. I very much appreciate the reply. Could our discussions please be private until any conclusion could be written which only paraphrases whatever of my questions were good and of course the entire Torah response?

I don't understand the logic of saying that because the 1 amah square region of the altar in Moshe's time was most likely (see below * for a problem with that) covered with these blocks of wood that in the time of the Beis HaMikdash its larger altar was also fully covered. Isn't it explicit that there were multiple simultaneous small fires on the altar in the time of the Beis HaMikdash? There would be no need to put one set of logs of wood on top of the entire altar, and in fact it might be a violation of wasting the wood-offering or communal-wood or Temple-owned wood resources.

* My rabbi mentioned that one explanation for the half-tefach border listed in the Gemara is that if in fact the Ma'arachah was fully covered then there would be no way for the wood to catch on fire or for the fire to reach the korban. Perhaps it would simply smother the fire out? The half-tefach border gives a place for the flame to come up and touch the wood so that it catches on fire.

My rabbi complimented my son's and my approach that the half-tefach border effect could be accomplished by the gap between an inscribed square and its square - that this was a good resolution to that problem.

Still our simplistic approach is that trees are round in cross section. Even if not a perfect circle, Moshe, if using a "slice" for a block of wood (rather than split wood) would still want to measure its major and minor axis diameters before cutting to be sure that its not more than an amah, to avoid sticking out without trimming, and to be close enough to an amah that it will work for the intended purpose, and possibly be large enough to still stack the korban on top of it.

Such a diameter measurement could be done with an outside caliper - just 2 parallel bars 1 amah apart.

Slicing a tree trunk that is 1 amah in diameter could be done with 2 saw cuts. I have seen table tops sliced from large trees in this fashion.

With the above overview, could I please have some more inside scoop as to how someone learning this sugya would come to understand the issues? All that I know from the text itself is just the few lines of the main text. I did not even know until my rabbi told me recently (in response to my urgent plea, to which you replied as well, since maybe I was completely off base as to what the daf was saying) that the small amah vs large amah issue is disputed.

Could you please take me through from the few lines of the daf through to the Sefas Emes touching upon Rashi and Tosfos and other commentaries who deal with aspects of these points?

The rabbi who learned through this drasha with me -- our purpose was to understand why the Torah Temimah cited it as relevant to the particular passuk in Parshas Vayikra -- must have had some additional commentaries in mind when explaining what the daf says. The extent of what I knew was that there is a small amah and a large amah and they differ by 1 tefach and that gave the border. From there I immediately tried to do the math calculation for the difference in area and considered the difference in area between the inscribed circle and its square and thought that this might be more applicable especially since split wood (the way the Temple Institute shows their firewood depiction, and as described in the Akeidah - that Avraham "split" the wood) would be much thinner rectangular pieces with gaps between them when covering an area. I would not call split wood as "blocks" because they are irregularly shaped with a wedge cross section.

Finally...

As to the connection to the time of the Beis HaMikdash, the same rabbi explained the blocks of wood that the kohanim had to carry up to the altar, and the Torah Temimah counted the exact number of kohanim involved for morning and afternoon korbanos and how many blocks each one carried. So again it is quite possible that I am fixating too much on the English word "block", and I should also not be too concerned that in a time of hewn stone that there might have been any lacking in "milling" capability for a softer material - wood.

If wood was milled to regular blocks there would certainly be a lot of saw dust, more so than just when chopping and splitting wood. If saw dust has a use, such as on the floor of a butcher shop years ago, for covering over blood from shechting korbanos, this might be a source for that material.

I am asking this because if in fact there were regular blocks of wood, possibly there would be some mention of the accumulated residue from milling the wood?

Chaim Chesler

Please note that the while the blocks of wood were a square Amah, they were not a cubic Amah. Rather, the thickness was less then 1/2 of an Amah. (See Shitah Mekubetzes to Zevachim 62:3. See also Rambam Hilchos Isurei Mizbe'ach 7:3.

However, the first opinion in Yerushalmi Shekalim 6:4 seems to maintain - contrary to the opinion of the Bavli - that the thickness of the blocks was *greater* than their length or width. According to the Korban Ha'Edah, the second opinion in the Yerushalmi argues and concludes, like the Bavli, that their thickness was less than their length. But according to the Pnei Moshe, the second opinion agrees with the first opinion and simply adds that the blocks were placed one on top of the other (not like the Shitah Mekubetzes).

Best wishes,

Y. Zirkind

Consulting the Artscroll Gemara and the various Kollel archives it seems that the thickness of the square blocks is not only as thin as the rod used to level something, but also at risk of being floppy. I take this to mean thinner than a book shelf.

I was taught by my rabbi that the thickness was half a tefach but could not find a written source for this.

Chaim Chesler