Daf Yomi:Twin Firstborn Sheep

Twin Firstborn Sheep – Which Is the Bechor?

“It Is Impossible to Ascertain Exactly”

(Bechoros 17b-18a)

Our Gemara continues the discussion based on the Mishna (17 a-b). R. Yosi Haglili rules that in a case where two firstborn male sheep emerge from their mother’s womb simultaneously, both are deemed to have the status of bechor and, as such, both must be given to the kohen. The Sages dispute his ruling, as in their view, it is impossible to ascertain the exact moment when each emerged.

Human Design

D’bei R. Yanai question whether the Sages’ rule of “Iy efshar l’tzamtzem” (It is impossible to ascertain matters with such exactness) applies only to matters that are bi’ydei Shomayim – beyond the scope of human design. Thus, where human design is involved, a simultaneous event can occur and be discerned as such. Or does this rule apply even to the result of human creativity?

Rashi (s.v.“v’kol sheken, iy efshar l’tzamtzem”) explains that perhaps the Sages invoke this rule only as regards random occurrences that generally do not occur simultaneously (such as twins emerging at exactly the same moment). But perhaps they may agree in principle that two things can occur at the same time when by intent, it was designed that way.

Human Frailties

Tosafos (s.v. “iy efshar l’tzamtzem”) explain differently and maintain that the issue at hand is not whether it is possible for two events to occur simultaneously. Indeed, the Sages agree that at times two things do occur at the very same moment – even when that is not the result of deliberate design. The Sages base the question on the human inability to make a positive determination as to whether the two occurrences were indeed simultaneous. Thus, in effect, according to the Sages, since we cannot make that determination, we treat the two occurrences as if they were not simultaneous. Similarly, regarding the birth of twins, we cannot be absolutely certain that they were born at exactly the same time.

In answer to this question, D’bei R. Yanai seem to suggest that the Sages apply the rule of “iy efshar l’tzamtzem” – that it is impossible to ascertain matters with exactness – only as regards matters that happen suddenly and cannot be measured or clocked (again, such as the birth of twins). However, where the matter at hand is man-made and there is ample time to assess the situation, the rule will not apply.

The Gemara (18a) concludes that in the Sages’ view, the rule applies in all situations, whether those that are Heaven-decreed or those resulting from human action and ingenuity.

Z'manei HaYom

A point to ponder: In our era, is it possible for two timepieces (individually controlled – not radio or atomic clocks) to keep exactly the same time and sound their alarms at exactly the same time? Indeed, many watchmakers boast that their products can so perform. But are their claims to be believed and relied upon?

We seem to rely on the accuracy of timepieces with a differential of a minute or two when it comes to various z’manim, whether z’man tefillah, z’man Kerias Shema, candle-lighting time for Shabbos, etc. It must therefore be the case that even though we are very dependent on these instruments, we throw caution to the wind and allow for some margin of error, no matter how small.