Siman 81

We learn at the end of the third chapter of Sukkah (42b): A minor who is able to eat a kezayit of dagan—one must distance oneself from his excrement and his urine four amot. And this is provided that he can eat a kezayit within the time of kedei achilat pras. But regarding an adult, even if he cannot eat within the time of kedei achilat pras. Rashi explained: All five species are called "dagan": wheat, barley, spelt, oats, and rye—one must distance oneself from his excrement once he has eaten a kezayit of these, in any manner of eating... Thus far his words. That is to say: whether he ate them dry, or whether he ate them moist or soaked and cooked, such as in the food they make for an infant which they call "papa" (Magen Avraham). And the measure is that he eats a kezayit of them within the time of kedei achilat pras: for an average person this is four eggs, and according to the Rambam three eggs. But if the minor needs to linger more than this measure—behold, he is like one who eats half a kezayit today and half a kezayit tomorrow, for this is a Halacha LeMoshe MiSinai that eating does not combine with a lingering longer than this (Rashi).

Some say that even if this child is naturally weak such that he cannot eat a kezayit of grain, but he has reached the stage where others like him are able to eat a kezayit of grain within the time of achilat pras – one must distance oneself from his excrement and his urine. This is the opinion of our teacher, the Beit Yosef, in section 1, see there. And in his great book, he explained that the opinion of Rashi is not so, and according to Rashi we require that he himself specifically be able to eat, see there. And there is one who says that the opinion of Rashi is also thus (Taz). However, several of the great authorities ruled like Rashi, and wrote that all the poskim hold thus, that we require that he himself be able to eat a kezayit of grain within the time of achilat pras. And they wrote further that even if he is able to eat, if it has been several days since he ate a kezayit of grain – one does not need to distance oneself from his excrement and his urine, even though regarding an adult it is not so (Bach, and Magen Avraham, and Eliyah Rabbah, and Pri Chadash). For regarding an adult, there is certainly no distinction whether he ate or did not eat, or between being able to eat and not being able to eat, for from all of them one must distance oneself, as is explained in the Gemara ibid.

And know that from the Yerushalmi, chapter three (halacha 5), there is a proof for our teacher, the Beit Yosef. For it says there: It was taught: A minor who is able to eat a kezayit of grain – one must distance oneself from his excrement… They asked before Rabbi Abbahu: Why does one distance oneself from his excrement…? He said to them: Because his thoughts are evil. They said to him: But is he not a minor? He said to them: And is it not written: "For the inclination of man's heart is evil from his youth"? It is written "from his youth"… Thus far his words. And it is not understood what they asked, "Why does one distance oneself from his excrement," for did it not explain previously that it is because he is able to eat a kezayit of grain? Rather, it is certainly according to the words of our teacher, the Beit Yosef, that it is only if he is able to eat, even though he did not eat. And consequently, if his years have reached the point that others are able to eat, even if he is not able to eat – one must distance oneself from his excrement. And for this they asked well: Why does one distance oneself from his excrement, for he did not eat or is not able to eat? And he answered them: Because his thoughts are evil. And this is in the manner that our sages, of blessed memory, said in Sukkah there: "He who increases knowledge increases pain." That is to say: that when he reaches this stage – everything he eats becomes foul (and see Peri Chadash).

There is one who wrote that in Yoreh Deah siman 265, section 8, it is implied that it is good and proper to distance oneself from the excrement of a minor even one eight days old (Magen Avraham subsection 1). And his intention is for what I wrote there, that one must clean the minor of his excrement before one recites the blessing over the milah, see there. And this is no proof: for there, because he is occupied with the minor himself to bring him into holiness—it is certainly a beautification of the mitzvah that he be clean and beautiful. And it is no less than the beautification of the mitzvah in all mitzvot. But what relevance does this have to one who prays in a house or recites Kriat Shema and there is a minor there? And so it implies explicitly in the great book of our teacher, the Beit Yosef, there, see there. And there is one who wrote that it is not proper to recite Kriat Shema near an infant, for a typical infant wallows in refuse (ibid. in the name of the Rashal). And furthermore: that they do not wipe themselves. And excrement at the orifice of the rectum, even if it is covered—is forbidden, as I wrote in siman 76 (ibid.). And for this reason, when he is wearing a garment—it is permitted, just as it is with covered excrement. Therefore, if he is wearing a garment, and they see that his hands are clean—there is no concern in this.

The Tur and the Shulchan Aruch wrote in section 2: If one was reciting and saw tzoah opposite him – he should walk so that he casts it four amot behind him. And if it is impossible, such as if there is a river before him or another thing that prevents it – he should walk so that he places it four amot to the sides. Thus far his words. And we have already explained in siman 79 section 3 that even though the sides have the same law as behind him, nevertheless here, where he is forced to turn from the place where he stands because the tzoah is opposite him – it is better that he cast it behind him than to the sides if it is possible for him.

And know that there is one who raised a difficulty: How is it relevant to say "it is impossible to cast it behind him," let him turn his face (Magen Avraham, subsection 3)? And he was pressed in this. But in truth, according to what we have explained, it is not a difficulty at all, for the sages did not impose any burden upon him in this. And this is the explanation: If he was reciting Shema and walking on the way, and sees excrement in front of him – he should go on his way until he casts it behind him. And if it is impossible – he should walk so that he leaves it to the sides. That is to say: that one should not impose upon him that he must turn his face and stop from his walking. Rather, he should go on his way and estimate so that he leaves it to the sides.

When he paused until he cast it behind him or to the sides—he only needs to return to the place where he stopped. For since it was not within his four amot—he was not required to check. And if he delayed long enough to finish the entire prayer—he returns to the beginning. Our teacher Yonah wrote: If he was in a place where he should have considered that there might be excrement there—he must return to the beginning. Thus far his words. The Rashba disagrees on this. And the primary view is like the opinion of the Rashba (Beit Yosef), for they were not so stringent regarding that which is opposite him. Therefore, they did not say "his prayer is an abomination" (ibid.).