The Mishna distinguishes between the marrow-bones (kulit) of a corpse or consecrated sacrifices of pigul and notar (kodashim) and those of a carcass (neveila) or a creeping creature (sheretz). Touching a corpse or sacrificial marrow-bone imparts impurity whether sealed or perforated, whereas a neveila or sheretz marrow-bone imparts impurity through touch (maga) and carrying (masa) only if perforated.

The Gemara notes that the Mishna specifies that a corpse's marrow-bone imparts impurity through touch (maga), but omits tent-impurity (ohel), and analyzes why:

• Rav Yehuda son of Rabbi Chiyya concludes that there is less than an olive-bulk (kezayit) of marrow, and that interior marrow does not halakhically heal or complete the bone's exterior (mo'ach bifnim eino ma'aleh arucha mibachutz).
• Abaye maintains that interior marrow does heal the exterior, but interprets the Mishna as speaking of a bone scraped thin (sheshifah) along its circumference.
• Rabbi Yochanan holds that the Mishna's term "touch" (maga) actually includes tent-impurity (ohel). To resolve a difficulty, the Gemara explains that the marrow inside is loose and rattling (mitkashkesh); for a corpse, compressed impurity breaks through (boka'at v'olah), whereas for neveila, loose marrow requires a physical perforation to transmit impurity.

Two proofs are brought from Mishnayot in Ohalot in an attempt to demonstrate that the term maga can denote ohel, but difficulties are raised against both suggestions.