Keilim 27:4-5
Keilim 27:4
If someone cuts from any of the aforementioned textiles a piece one handbreadth by one handbreadth, it is susceptible to impurity. A square handbreadth from the bottom of a basket is also susceptible to impurity but if one cuts from the sides of a basket, Rabbi Shimon says it is insusceptible to impurity. The Sages say that if someone cuts a square handbreadth from anywhere, it is susceptible to impurity.
Keilim 27:5
Rabbi Akiva says that worn-out sifters or sieves that were modified for use as a seat are susceptible to impurity; the Sages say that they’re insusceptible unless they’ve been trimmed. A child’s chair that has legs is susceptible to impurity even if it’s less than a handbreadth high (about 3”). Rabbi Eliezer says that a child’s shirt is susceptible to impurity in any size but the Sages say that it’s only susceptible to impurity if it’s the requisite size for its material, measured when doubled over.