English: “On the wood that is on the fire” — wood that is placed to become fire (to exclude vine and olive wood, which become ash too quickly).
In the sugya: Not every wood is “wood that is on the fire.” Vine and olive burn down too fast; they are not the sustained fuel the phrase describes. The ma’arachah requires woods that hold a proper fire.
Type of Learning
Miyut of unsuitable woods from “wood that is on the fire” — vine and olive excluded.
What Is Learned
Only woods that sustain a proper altar fire are used; vine and olive are excluded from the ma’arachah. “Wood that is on the fire” selects fuel that is meant to remain fire, not flash to ash.