Is Impossible Pork Kosher?

(1) One who buys a tallit with tzitzit attached from a Jew or from a non-Jewish merchant, [Rema: and he says that he bought it from an honest Jew] (N"Y laws of tzitzit) [the talit] is kosher; since he is a merchant there is a presumption that he bought it from a Jew because he wouldn't harm himself. But, if one bought it from a non-Jew who is not a merchant, it is invalid.

(2) In three baskets each of [the capacity of] three seahs they make the appropriation [of shekels] from the chamber. And on them was inscribed: Aleph, Beth, Gimmel. Rabbi Ishmael says: Greek was inscribed on them, alpha, beta, gamla. The one who made the appropriation did not enter the chamber wearing either a bordered cloak or shoes or sandals or tefillin or an amulet, lest if he became poor people might say that he became poor because of a sin committed in the chamber, or if he became rich people might say that he became rich from the appropriation in the chamber. For it is one’s duty to be free of blame before others as before God, as it is said: “And you shall be guiltless before the Lord and before Israel” (Numbers 32:22), and it says: “And you will find favor and good understanding in the eyes of God and man” (Proverbs 3:4).

(9) Fish blood, although it is permissible if gathered in a container, is forbidden on account of looking bad. Thus, if it is apparent that it is from fish — for instance, if there are scales in it — it is permitted.

(3) ...RAMA: We make milk from almonds and place bird meat in it, since [milk and bird meat] is only rabbinically [forbidden]. But with meat from a domesticated animal, place almonds next to the milk, so that people don't misunderstand. This is as we said above, in chapter 66.

Whenever the sages prohibited something because of 'marit ayin' [it is because] the person who sees him will suspect him of violating a transgression.

[Fish blood] was placed - in a vessel it would be prohibited because it might be confused for animal blood and a bystander might conclude that it is permissible to eat blood.

Rav Yehuda said that Rav said: Wherever the Sages prohibited an action due to the appearance of prohibition, even in the innermost chambers, where no one will see it, it is prohibited. When prohibiting an action because of marit ayin, the Sages did not distinguish between different circumstances. They prohibited performing the action in all cases.

"and judge every person as meritorious:" Its subject is when there is a person whom you do not about him if he is righteous or if he is wicked and you see him doing an act or saying something and if you interpret it one way it will be good and if you interpret in another way it will be bad - [in this case,] take it to the good and do not think bad about it...And it is not permissible for you to suspect him; and about this did they say (Shabbat 97a), "The body of anyone who suspects proper ones (choshed b'ksheirim) will be struck"...But when he is not known and the deed is indeterminate towards one of the two extremes; according to the ways of piety, one must judge a person as meritorious towards whichever extreme of the two extremes [would be the case].

The only mixture that creates the prohibition of kilayim is sheep and lambs wool with flax...and the Sages prohibited because of marit ayin to mix silk with wool because [silk] is similar to flax...but nowadays where silk is commonly found in our region and everyone recognizes it, there is no prohibition of marit ayin and it is permissible to mix it with wool or flax.

The wool of a sheep born from a goat is prohibited to mix with flax because of marit ayin. Haga: it is prohibited to sew a nylon garment under a wool garment in a place where nylon is not commonly found because of marit ayin (Tur quoting the Rosh) but in a place where it is commonly found it is permissible.