Eiruvin 9:4-10:1

Eiruvin 9:4

If a person builds an upper level across two houses (that are on opposite sides of a public domain), one may carry under it, and the same rule applies to bridges that have roads passing under them. This is the opinion of Rabbi Yehuda; the Sages do not allow it. Rabbi Yehuda also said that one can make an eiruv for an alley that is a through road (i.e., open on two sides) but the Sages do not permit this.

Eiruvin 10:1

If a person finds tefillin on Shabbos, he may transport them to a safe place a pair at a time (by wearing them). Rabban Gamliel says he may transport two pair at a time. This refers to tefillin that already have the knots tied; if one finds tefillin that have not yet had their knots tied, he need not bring them in (because they may not even really be tefillin). If he found many tefillin, either in pairs or in one big pile, he should wait with them until Shabbos ends and then bring them in. If it’s a dangerous situation, he should cover them and go on his way.