Bava Batra

What [need was there for Scripture] to say, He may not make [the son of the beloved] the firstborn?  — Since it was said, Then it should be, in the day that he causeth his sons to inherit,  one might argue that it is a matter of logical deduction, [thus:]  If [in the case of'] an ordinary [son], who is privileged to receive [a share] in any prospective [property of his father] as in that which is actually in his possession, the Torah [nevertheless] gave authority to the father to transmit [his estate] to whomsoever he pleases, how much more [should he have this right in the case of] a firstborn, whose rights are impaired in that he does not receive [the portion of the birthright] in prospective property as in that which is actually in the possession [of his father]; hence it was expressly stated, He may not make [the son of the beloved] the firstborn. Then let Scripture say, He may not make [the son of the beloved] the firstborn,  why should it [also] state Then it shall be, in the day that he causeth his sons to inherit? — Because one might [argue], is not this a matter of logical deduction?  If [in the case of] a firstborn, whose rights are impaired in that he does not receive [the portion of his birthright] in prospective [property] as in that which is actually in [his father's] possession, the Torah, [nevertheless,] said, He  may not make [the son of the beloved] the firstborn, how much less [should he have this right in the case of] an ordinary [son] who is privileged to receive in prospective [property] as in that which is actually in [his father's] possession; hence it was expressly stated, Then it shall be, in the day that he causeth his son to inherit, [in order to make it clear that] the Torah gave a father authority to transmit his estate to whomsoever he pleases. R. Zerika said in the name of R. Ammi in the name of R. Hanina in the name of R. Jannai  in the name of Rabbi: The halachah is in agreement with [the views of] R. Johanan b. Beroka. R. Abba said to him: The statement was that he [only] gave [such] a decision!  Wherein lies the difference?  — [One] Master holds [that] an halachah is preferable  and the [other] Master holds that a practical decision is [of] greater [importance]. Our Rabbis taught: The halachah  may not be derived either from theoretical [conclusion] or from a practical [decision] unless one has been told [that] the halachah [is to be taken as a rule] for practical decisions. [Once a person has] asked and was informed [that] an halachah [was to be taken as a guide] for practical decisions, he may continue to give practical decisions [accordingly],  provided he draws no comparisons.  What [could be meant by], 'provided he draws no comparisons'? Surely, in the entire [domain of] the Torah comparisons are made! — R. Ashi said: It is this that was meant: Provided one draws no comparisons in [ritual questions relating to] trefoth.  For it was taught: In [the laws of] trefoth it must not be said this [one] is equal to that.  And do not be astonished [at this], for [an animal] may be cut on one side  and die, [yet when] it is cut on another side  it remains alive. R. Assi said to R. Johanan: 'May we, when the Master tells us:  "The halachah is so and so," give a practical decision accordingly?' He said: 'Do not use it as a practical guide  unless I declare [it to be] an halachah in [connection with] a practical decision.' Raba said to R. Papa and to R. Huna the son of R. Joshua: 'When a legal decision of mine comes before you [in a written form], and you see any objection to it, do not tear it up before you have seen me.  If I have a [valid] reason [for my decision] I will tell [it to] you; and if not, I will withdraw. After my death, you shall neither tear it up nor infer [any law] from it. "You shall neither tear it up" since, had I been there, it is possible that I might have told you the reason;