Keilim 29:2-3

Keilim 29:2

Three wool cushions, six linen cushions, three sheets, twelve handkerchiefs, two pants, one shirt, one cloak or one blanket can be considered connected for purposes of ritual impurity and sprinkling (for purification). More than this are considered connected for purposes of impurity but not for sprinkling. Rabbi Yosi says they’re not even considered connected for impurity.

Keilim 29:3

The string of a lay person’s plumbline is considered connected for up to 12 cubits (about 18 feet); one of carpenters, up to 18 cubits (about 27 feet) and one of professional builders up to 50 cubits (about 75 feet). Longer than this is insusceptible to impurity even if the user chooses to retain the surplus length. The plumblines of plasterers and artists are considered connected whatever their length.