The central act in the process of proving through Divine intervention the guilt or innocence of a sotah (suspected adulteress) is her drinking the special potion known as the "cursed waters."

The Torah three times (Bamidbar 5:24, 26, 27) directs that she must be given this potion to drink, and the simple understanding is that she drinks it from a cup. The Sage Rava poses an interesting question: What if she drinks it by way of a siv -- is this considered a normal way of drinking or not?

Rashi explains siv as a drinking straw formed from the bark of a palm tree. The Aruch, however, writes that the siv bark served as a sort of sponge to absorb the potion which was subsequently sucked out of the siv by the sotah.

It may be that the Aruch departs from Rashi's approach because the next question posed by Rava is whether drinking through a shfoferet qualifies as normal drinking. The literal translation of this word is "tube", so defining siv as a straw would make the two questions identical. A solution to this problem facing Rashi is provided by Tosefot Shantz who defines the shfoferet mentioned in Rava's second question as only being similar to a straw, but really a sieve through which the potion flows into the sotah's mouth.

According to either explanation of siv, the question is raised by Tosefot as to why we do not resolve Rava's question on the basis of what he himself says (Mesechta Pesachim 155b), that if one wraps a siv around matzah on Pesach Eve and thus swallows it he has not fulfilled the mitzvah of eating matzah. Just as siv around matzah is not considered normal eating, so should drinking through siv not be considered normal drinking.

Tosefot quickly dismisses the comparison by pointing out that in the case of matzah, the siv bark forms a barrier between the matzah and the food pipe and is therefore not considered normal eating. This is not the case with the potion which enters the food pipe unobstructed but through an unconventional channel.

"For the mitzvah is a candle and Torah is light." (Mishlei 6:23) This is comparable, says the gemara, to the situation of a man walking along a lonely road in total darkness. He is afraid of the thorns which may cut him, the sword-like growths which may stab him and the pits into which he is likely to fall. In addition he is in fear of the wild beasts and bandits which lurk in the darkness and he is not certain that he is walking in the right direction.

He comes upon a torch to light his way and is now able to avoid thorns, sword-like growths and pits. But he is still in fear of beasts and bandits and uncertain of his direction. When the light of dawn appears he is safe from the beasts and bandits who slink back to their lairs but he is still uncertain of where he is heading. Only when he reaches a familiar crossroads is he finally free from all the dangers which have threatened him.

Maharsha explains this parable in the following fashion:

Life in this world is compared to a journey through darkness. Man is composed of body and soul. The body performs the mitzvot, while the soul, which encompasses man's intelligence, is occupied with the intellectual activity of Torah study. In man's physical existence there are three major obstacles to security and perfection. Thorns symbolize man's struggle against hunger as we find in the penalty of human labor meted out to Adam. "Thorn and thistle will it [the earth] sprout for you" (Bereishet 3:18). The sword-like growth represents the sword of the enemy and the pits symbolize the sudden death of sickness and accident. Performing mitzvot with our physical powers is similar to the torch and the merit of these physical actions achieves for us physical security.

But man is also threatened in regard to his spiritual security. The evil inclination in man is like the beast within while the evil influence of bad company is like the bandit outside. These spiritual dangers can only be countered by the spiritual-intellectual force of Torah study which is like the light of day.

What do the crossroads, which bring final security, represent? A number of definitions are offered by the Sages. Rabbi Nachman bar Yitzchak states that this means a Torah scholar with fear of sin. Rashi explains that if one has achieved the self-discipline of fearing sin after achieving Torah knowledge, he is safe from all dangers, for Torah educates him in regard to his responsibilities and what is right and wrong while self discipline restrains him from following his passions. This is called finally knowing that one is heading in the right direction.