Muhammad says that one day the very trees and stones will help Muslims to kill Jews

He says it in both Sahih al-Bukhari and Sahih Muslim, Islam's two most canonical hadith collections:

Sahih al-Bukhari, Volume 4, Book 56, Number 791:

Narrated 'Abdullah bin 'Umar:
I heard Allah's Apostle [Muhammad] saying, "The Jews will fight with you, and you will be given victory over them so that a stone will say, 'O Muslim! There is a Jew behind me; kill him!' "

Sahih al-Bukhari, Volume 4, Book 52, Number 176:

Narrated 'Abdullah bin 'Umar:
Allah's Apostle said, "You (i.e. Muslims) will fight with the Jews till some of them will hide behind stones. The stones will (betray them) saying, 'O 'Abdullah (i.e. slave of Allah)! There is a Jew hiding behind me; so kill him.' "

Sahih al-Bukhari, Volume 4, Book 52, Number 177:

Narrated Abu Huraira:
Allah's Apostle said, "The Hour will not be established until you fight with the Jews, and the stone behind which a Jew will be hiding will say. "O Muslim! There is a Jew hiding behind me, so kill him."

Sahih Muslim, Book 041, Number 6981:

Ibn 'Umar reported Allah's Messenger [Muhammad] (may peace be upon him) as saying: You will fight against the Jews and you will kill them until even a stone would say: Come here, Muslim, there is a Jew (hiding himself behind me); kill him.

Sahih Muslim, Book 041, Number 6983:

Abdullah b. 'Umar reported Allah's Messenger (may peace be upon him) as saying: You and the Jews would fight against one another until a stone would say: Muslim, here is a Jew behind me; come and kill him.

Sahih Muslim, Book 041, Number 6984:

Abdullah b. 'Umar reported that Allah's Messenger (may peace be upon him) said: The Jews will fight against you and you will gain victory over them until the stone would say: Muslim, here is a Jew behind me; kill him.

Sahih Muslim Book 041, Number 6985:

Abu Huraira reported Allah's Messenger (may peace be upon him) as saying: The last hour would not come unless the Muslims will fight against the Jews and the Muslims would kill them until the Jews would hide themselves behind a stone or a tree and a stone or a tree would say: Muslim, or the servant of Allah, there is a Jew behind me; come and kill him; but the tree Gharqad would not say, for it is the tree of the Jews.