Leviticus 11:8

Of their flesh you shall not eat, nor touch their carcase; they are abominable to you.

do not touch their remains Scripture does not mention that someone who does touch their remains is ritually impure until evening, but we know this from tradition. Moreover, it is a corporal offense to touch their remains deliberately, since by so doing, one violates a prohibition [see also Deuteronomy 14:8]. If we were to follow the literal meaning of the verse, without exegetical explanation, we would not permit ourselves to eat fish that are found in lakes, since the verse specifies seas and streams only.

AND THEIR CARCASSES YE SHALL NOT TOUCH. This is not a prohibition [saying that] we are not to touch these carcasses [of the animals that we are forbidden to eat]. Rather, Scripture states, and their carcasses ye shall not touch, for they are unclean to you, meaning to say, “you cannot touch them without becoming unclean.” The meaning thereof is to state that all those who touch them should be aware that they have become unclean and should therefore be careful not to enter the Sanctuary nor [to eat] of the hallowed offerings. Perhaps the meaning of the interpretation which our Rabbis have said: “And their carcasses ye shall not touch — on a festival” is to say that “you should not touch them at a time when you want to be clean, for they are unclean [and by touching them you will also become unclean] and you will not be able to go up to the Sanctuary on the festival.” But the [mere] act of touching them is not forbidden by means of a negative commandment, for he who touches carrion [even] on a festival does not incur whipping [by law of the Torah]. Thus that which the Rabbis have said: “One is dutybound to purify oneself on a festival,” is a commandment of Rabbinic authority, there being according to Scriptural law neither a positive nor a negative commandment, concerning the touching of carrion, except that of going up to the Sanctuary. Or it may be that the interpretation, “And their carcasses ye shall not touch — on a festival,” is a Scriptural text used as a support for the Rabbinical enactment,, p. 314, Note 449. like many other laws of the Sages taught there in the Torath Kohanim, which use Biblical texts as a “support.” It is also taught there: 2:6. “Other Rabbis (others). See Horayoth 13 b, for the reason of this name. say: One might think that if a person touches a carcass [he violates a negative commandment and] is liable to whipping? Scripture therefore says, By these ye shall become unclean. From this one might think that if a person sees a carcass he must go and render himself unclean by [touching] it? Scripture therefore says, and their carcasses ye shall not touch. How are we to reconcile these two verses? We must conclude that [touching a carcass] is optional” [i.e., neither obligatory, nor forbidden]. This is the main principle of the Scriptural law.

ובנבלתם לא תגעו. At a time when you need to touch sacred matters or when you are about to eat sacrificial meat, for instance, you are not to touch the dead bodies of such creatures, as we know from כל הנוגע בהם יקדש, (Exodus 30,29) “anyone touching it (the altar) will become (must become) holy.” (consecrated) [In other words, before coming into contact with something sacred one must first become ritually pure, as otherwise one cannot share the sanctity with the object one wishes to consume. Ed.] The legislation mentioned here applies also to touching holy vessels, or the altar, or anything concerning which the Torah has written the words כל הנוגע בהם יקדש.