The Gemara says being makdish a baal mum should be like being makdish a dekel tree ie wood, as if a wood korban is absolutely nothing. But we've seen before in gemaras a shita that wood could be a korban !
Menachem Weiman, St Louis, MO
That is special wood! This is the opinion of Rebbi (Menachos 20b) and applies only to the two planks of wood. If someone is Makdish other wood, he does not intend it to be a Korban but rather that it should be for Bedek ha'Bayis, so its monetary value becomes Hekdesh but the wood does not possess Kedushas ha'Guf.
Dovid Bloom
Thanks. Where do the meforshim say that Rebbi is only referring to the special two blocks of wood?
The Chidushei ha'Griz (Stencil, Menachos 20b, page 31) writes that according to Rebbi it is only if he says "Harei Alai Shnei Gizrei Etzim l'Mizbe'ach" -- "I obligate myself to bring the two planks of wood for the Mizbe'ach," that it becomes a Korban.
Dovid Bloom