פירוש על טהרות 6:8

בסילקי (basilica, a building with colonnades for holding courts, meeting place for merchants, exchange) – a large wide street/open place. And this is what we said in Chapter two of [Tractate] Yoma [folio 24b] the chamber of hewn stones was like a large basilica/building with colonnades for holding courts.

A basilica: is a private domain in respect of the laws of Shabbat but as a public domain in respect of those of uncleanness. A basilica is a large building through which many people pass. Probably something akin to city hall in our day. When it comes to Shabbat it is still a building and therefore it is considered a private domain. However, when it comes to the laws of uncleanness since so many people pass through and it is a public building, it is considered a public domain.

ורואה את הנכנסים ואת היוצאים- for when he sees those who enter and those who leave it is considered more a private domain. But the Halakha is not according to Rabbi Yehuda.

Rabbi Judah says: if one is standing at one door can see those that enter and leave at the other door, it is regarded as a private domain in both respects; otherwise it is regarded as a private domain in respect of Shabbat and as a public domain in respect of uncleanness. Rabbi Judah adds a criterion to the definition of when a basilica is a public or private domain. If it is small enough so that one standing at one door can see the other door, then it is a private domain. If it is larger than that, he agrees with the previous opinion.