Why did He command him to prophesize about the bones?
Malbim: The future revival will be from a body that decayed in earth, like man's creation in the womb. First there is skin all around the drop of seed, and from when there is flesh ? "che'Chalav Taticheni vecha'Gevinah Takpi'eni; Ohr u'Vasar Talbisheni uva'Atzamos v'Gidim Tesochecheni" (Iyov 10:10-11) ? skin before flesh. Afterwards the limbs are tied with sinews and bones. Also, [the future] revival will be from the Luz bone, which has some life, and it is like seed from which the body will sprout ? unlike these dry bones without life. Therefore, Nevu'ah was needed 1 .
Why is Nevu'ah needed for a miracle unlike the normal method? Moshe cured bitter water via bitter wood (Shemos 15:25, Shemos Rabah 23:3), and Elisha cast wood into water to make iron float (Melachim II, 6:6) without a Nevu'ah! (PF)
