פירוש על שבת 45:8

One may use it to establish an eiruv: The joining of courtyards and the joining of borders.

Establish the merging in an alleyway. For if one wants, he can render his property ownerless and become poor; and [then the produce] would be fit for him. As we learn (in a mishnah), "We feed demai to the poor." Hence it is considered his.

And one recites a blessing: HaMotzi.

And one invites [a quorum]: This is the blessing of invitation.

And one may separate it: A person who is naked. Meaning to say that there is no need to recite a blessing upon it when he separates it.

"Therefore shall your camp be holy that He see no unseemly thing in you" - even the speech, of mentioning [God's] name, should see no unseemly thing in you.

A definite rabbinic law: Such as the Channukah lamp.

An uncertain rabbinic law: Such as demai. Since [the need for] its separation is only from an uncertainty.