בבא בתרא ח׳:ה׳ - ח׳:ו׳

לא אמר כלום – and he is not able to remove hm from the inheritance, other that via that he would give his property to the rest of his sons through a gift.

על פיו – because it is a Mitzvah in the consequence of a death and a person on his deathbed, his words are like they were written and transmitted and they don’t require an [act of] acquisition, and because of this it is taught “by his mouth”/על פיו.

והשוה להן את הבכור – in the language of a gift.

דבריו קיימין – and we don’t have here [the case] of a person making a condition against what is written in the Torah because it is within the power of an individual to give his money as a gift to whomever he desires.

ואם אמר משום ירושה – and if he increased [the monies] to one and lessened them to another in the designation of inheritance as he said: “So-and-so my son will a field that is an area requiring a Khor of seed, and so-and-so my son will inherit a field that is in an area requiring a one-half Khor of seed. But regarding his first-born son he said that he would inherit like that of his fellow, he did not say anything, for he made a condition that is against what is written in the Torah.

כתב בין בתחלה וכ' – “You will give such-and-such a field to son-and-so, and he will inherit it.” This is at the beginning. “He will inherit it and you will give it to him.” This is at the at the end. “He will inherit such-and-such a field and you will give it to him and he will inherit it. This is a gift in the middle.

אם אמר על מי שראוי ליורשו – as for example, regarding a son among the sons, or regarding a daughter among the daughters, so-and-so will inherit me, his words are fulfilled, as it is written (Deuteronomy 21:16):”When he wills his property to his sons [he may not treat as first-born the son of the loved one in disregard of the son of the unloved one who is older].” The Torah gave permission to the father to bequeath to the sons to whomever he desires. And Rabbi Yohanan [Ben Beroka] agrees regarding a brother in place of a daughter, and regarding a daughter in place of a son, he has not said anything for the daughter is not worthy of inheriting in place of a son nor is the brother [worthy of inheriting] in place of a daughter. And similarly, Rabbi Yohanan [ben Beroka] agrees that if he made the first born equivalent to the [other] sons, he has not said anything, as it is written (Deuteronomy 21:16): “he may not treat as first-born the son of the loved one.” And the Halakha is according to Rabbi Yohanan ben Beroka.

אין רוח חכמים נוחה הימנו – The Sages have no pleasure from his actions, and even if his sons did not conduct themselves appropriately. Perhaps, there will arise from them a higher-level seed. But the Halakha is not according to Rabbi Shimon ben Gamaliel.

זה בני נאנון – to inherit him and to exempt his wife from levirate marriage.

זה אחי אינו נאמן – to cause him to inherit with his brothers, for they do not recognize him.

ונוטל עמו בחלקו – as for example, if they are two brothers, besides the doubt, and they have to divide three fields, This one takes a field and one-half, and that one takes a field and one-half, and the third one testifies on the doubt that he is their brother, he gives him one-half of the field, but the other does not give him anything, or he says to him: “bring proof and then take.”

מת – [the one about whom there is] doubt.

יחזרו – those properties that his brothers gave him.

למקומן – meaning to say, to whomever had given them to him, but the other brothers do not inherit with him.

נפלו לו – to the one [about whom there is] doubt.

נכסים ממקום אחר – during his lifetime; or he bought property and now is dead.

ירשו אחיו – of the one who testifies that he is their brother.

עמו – for surely he admits to them that he is their brother, but these words [concern] when the rest of the brothers did not deny to state that he definitely is not their brother, but rather claim that they don’t recognize him, but if they deny that he is their brother, they do not inherit him other than the one who testified about him alone.

דיאתיקי – a will of someone on his deathbed. And the language of דיאתיקי is this what shall be established and come to pass.

קשורה לו ביריכו – that is not to say that after it was written and placed there, even so it is worthless, for he did not complete to transfer possession other than with the receipt of a document, but there is no document after death.