Bava Batra

— Because [the embryo] dies first  and no son in the grave  may inherit from his mother to transmit [the inheritance] to his paternal brothers 'Do you mean to say that it  dies first, surely there was a case when it made three convulsive movements?  — Mar. son of R. Ashi, replied: Those were only [reflex movements] like those of the tail of the lizard which moves convulsively [even after it has been cut of]. Mar, the son of R. Joseph, said in the name of Raba: This  teaches  that he  causes a diminution in the portion of the birthright.  [This] however [applies] only [to a child who is] one day old, but not to an embryo.  What is the reason? — The All Merciful said, And they have born to him.  For [so] said Mar, the Son of R. Joseph. in the name of Raba: 'A son who was born after the death of his father does not cause a diminution In the portion of the birthright. What is the reason? The All Merciful said, And they shall have born to him,  which is not [the case here]. Thus  it was taught at Sura. At Pumbeditha. [however]. it was taught as follows:  Mar. the son of R. Joseph, said in the name of Raba: A firstborn son who was born after the death of his father  does not receive a double portion. What is the reason? The All Merciful said, He shall acknowledge,  and, surely. he is not [alive] to acknowledge [him]. And the law is in accordance with all those versions which Mar the son of R. Joseph quoted in the name of Raba. R. Isaac said in the name of R. Johanan: If possession was given to an embryo [through the agency of a third party]. it does not acquire ownership. And if objection should be raised from  our Mishnah,  [it may be replied that there it is different] because a person is favourably disposed towards his son. Samuel said to R. Hana of Bagdad: 'Go. bring me a group of ten [people] and I will tell you in their presence  [that] if possession Is given to an embryo [through the agency of a third party]. it does acquire ownership'. But the law is that if possession is given to an embryo [through the agency of a third party]. it does not acquire ownership. Once a certain man said to his wife, 'My estate [shall belong] to the children that I shall have from you'. His eldest son  came [and] said to him, 'What shall become of me?'  He replied to him, 'Go acquire possession as one of the [other] sons'.  Those  [can] certainly acquire no ownership.  since they are not yet in existence; has [however]. this lad  an [additional] share beside  the [other] sons,  or has the lad no [additional] share beside  the [other] sons? — R. Abin and R. Measha and R. Jeremiah say: The lad receives an [additional] share beside the [other] sons. R. Abbahu and R. Hanina b. Papi and R, Isaac Nappaha say: The lad receives no [additional] share beside the [other] sons. R. Abbahu said to R. Jeremiah. 'Is the law in accordance with our view  or in accordance with yours?' He replied to him, 'It is obvious that the law' is in accordance with our view because we are older than you. and [that] the law' [can] not be according to your view because you are [only] juniors.' The other retorted, 'Does the matter then depend on age? [Surely] the matter depends on reason!' 'And what is the reason?' [R. Jeremiah asked.] 'Go to R. Abin,' [replied R. Abbahu.] 'to whom I have explained the matter