פירוש על חולין 3:7

ובחגבים – this is the sign of their pu- ity.

Introduction Some types of locusts are clean and can be eaten (see Leviticus 11:20-25). Our mishnah teaches the characteristics of locusts and fish that can be eaten.

כל שיש לו ארבע רגלים וארבע כנפים ויש לו קרסולים (see Leviticus 11:21- jointed legs) – they are two long legs outside of the four. And they are adjacent to its neck, above from its legs to leap with them when it wishes to jump, it strengthens itself with them.

Of locusts: all that have four legs, four wings, leaping legs, and wings covering the greater part of the body, [are clean.] Rabbi Yose says: its name must be locust. For a locust to be clean it must have four legs and wings. It must also have two legs above its other legs with which to leap (see Leviticus 11:21). And its wings must cover the greater part of its body. Rabbi Yose adds that it must be called a locust. If it has all of the signs of being kosher but it is not called a “locust” then it is not kosher. We can see here just how important a name can be to the status of the validity of the animal.

רבי יוסי אומר ושמו חגב – even though it has these four distinguishing marks, it is not kosher, other than if it is known that its name is locust. And this is the Halakha.

Of fishes: all that have fins and scales [are clean]. Rabbi Judah says: there must be [at least] two scales and one fin. The Torah states this rule explicitly, see Leviticus 11:9. Rabbi Judah adds that there must be at least two scales.

כל שיש לו סנפיר וקשקשת – even if it doesn’t have it now, and will in the future will grow one after a while, or that it has one now, and it will, in the future will drop it when it leaves the water (see Tractate Hullin 66a), it is permitted.

The scales are those which are immovable, the fins are those [wings] by which it swims. The mishnah now defines scales and fins. Scales are those that are immovable, meaning that the fish does not have control over them. Whereas the fins are like wings to a bird in that the fish swims by moving his fins.

וסנפירין הפורח בהם – that roam–swim with them over the face of the water.