Is the Doctrine of Resurrection of the Dead expressed in Pentateuch? What passages in the Pentateuch are commonly believed by Christians to teach the resurrection of the dead?



Background for this question:

After the Jewish people returned from Babylon most of them no longer spoke Hebrew and began to speak in Aramaic. Samaritans in Palestine argue that because the Jews lost their ability to speak Hebrew they could no longer correctly interpret the Pentateuch, which at that time was written with new alphabet. During the time of Jesus Christ, the Sadducees argued that the doctrine of resurrection of the dead was foreign to the early Israelites. To answer their allegation, Jesus quoted from Exodus 3:6,


  [F]or the resurrection of the dead, have you not read what was said to you by God, "I am (Gk.  ἐγώ εἰμι) the God of Abraham, and the God of Isaac, and the God of Jacob"? He is not God of the dead, but of the living. (Matthew 22:31-32)


But in the Samaritan Pentateuch there is no present indicative such as ἐγώ εἰμι,


  I [am] the God of thy father, the God of Abraham, the God of Isaac, and the God of Jacob. (Exodus 3:6, Samaritan Pentateuch)


Samaritans to this day argue that Rabbinical Judaism inserted new doctrine into Aramaic Targum to develop man made tradition unknown to the early Israelites prior to Babylonian captivity.


  By the labour of thy hands thou shalt eat food, until thou turn again to the dust from which thou wast created: for dust thou art, and unto dust thou shalt return; for from the dust it is to be that thou art to arise, to render judgment and reckoning for all that thou hast done, in the day of the great judgment. And Adam called the name of his wife Hava, because she is the mother of all the children of men. (Genesis 3:19-20, Palestinian Targum, my emphasis)
Ressurection is mentioned many times in the Bible. Job also said "And after my skin has been destroyed, yet in my flesh I will see God" (Job 19:26).

According to this article, the Sadducees based their doctrine only from the Torah(Pentateuch), rejecting all Jewish Oral Laws and gave no importance to the writing of the Prophets. 

In Matthew 22:23-33, Sadducees wanted to test Jesus on the topic of resurrection. Knowing that they accepted only the Pentateuch, Jesus replied them from the Pentateuch itself that resurrection is mentioned(perhaps indirectly). This reply from Jesus silenced the Sadducees.


  Hearing that Jesus had silenced the Sadducees, the Pharisees got
  together. One of them, an expert in the law, tested him with this
  question: (Matthew 22: 34-35, NIV)


Their silence would probably mean that Jesus was quoting correctly from the same Scripture that Sadducees were reading. Otherwise they should have argued about the tense used in the Scripture like the one you mentioned from the Samaritan Pentateuch. Also there was no reason why Sadducees would read from the Samaritan Pentateuch because Jews at that time abhorred the Samaritans.

So, to answer your question, "Is the Doctrine of Resurrection of the Dead expressed in Pentateuch?", the answer is definitely YES! according to Jesus or Christian Scripture. But if you ask "Is it mentioned in the Samaritan Pentateuch?", the answer could be 'No' but I think that is irrelevant for Christians because our Scripture is different from what the Samaritans have.