Hadith no. 2393 (below) is a repeat. Read about it here.
Volume 3, Book 50, Number 895 :
Narrated by Ibn ‘Umar (radiallaahu `anhu)
Umar bin Khattab (radiallaahu `anhu) got some land in Khaibar and he went to the Prophet (sallallaahu `alayhi wasallam) to consult him about it saying, “O Allah’s Apostle (sallallaahu `alayhi wasallam)! I got some land in Khaibar better than which I have never had, what do you suggest that I do with it?” The Prophet (sallallaahu `alayhi wasallam) said, “If you like you can give the land as endowment and give its fruits in charity.” So Umar (radiallaahu `anhu) gave it in charity as an endowment on the condition that would not be sold nor given to anybody as a present and not to be inherited, but its yield would be given in charity to the poor people, to the Kith and kin, for freeing slaves, for Allah’s Cause, to the travelers and guests; and that there would be no harm if the guardian of the endowment ate from it according to his need with good intention, and fed others without storing it for the future.”
Kitaab-ush-Shuroot [Book of Conditions] ends here.
Kitaab-ul-Wasaayaa [Book of Wills] starts today..
Volume 4, Book 51, Number 1 :
Narrated by Abdullah bin Umar (radiallaahu `anhu)
Allah’s Apostle (sallallaahu `alayhi wasallam) said, “It is not permissible for any Muslim who has something to will to stay for two nights without having his last will and testament written and kept ready with him.”
Allah says in the Quran:
“It is prescribed for you, when death approaches any of you, if he leaves wealth, that he makes a bequest to parents and next of kin, according to reasonable manners. (This is) a duty upon Al-Muttaqoon (the pious).” [al-Baqarah 2:180]
The Prophet (peace and blessings of Allaah be upon him) said:
“Allaah was being generous to you when He allowed you to give one-third of your wealth (in charity) when you die, to increase your good deeds.”
(Narrated by Ibn Maajah, al-Wasaayaa, 2700; classed as hasan by al-Albaani in Saheeh Sunan Ibn Maajah, no. 2190)
It is permitted to write a will concerning one third or less. Some of the scholars said it is preferable for it to be less than one-third, and the will does not apply to any of the heirs, because the Prophet (peace and blessings of Allaah be upon him) said:
“There is no will for the heirs.”
(Narrated by al-Tirmidhi, al-Wasaayaa, 2047; classed as saheeh by al-Albaani in Saheeh Sunan al-Tirmidhi, no. 1722).
The will comes into effect when the person dies. It is permissible for the person who writes the will to revoke it or cancel it or revoke part of it. Carrying out the will is an important matter which was confirmed by Allaah and mentioned before other things, and there is a stern warning issued to those who change it.
With regard to the distribution of personal belongings, he does not have the right to state how they should be distributed after he dies, because the share of each heir has been defined by Allaah, and He has explained who inherits and who does not inherit. So it is not permitted for any person to transgress the limits set by Allaah, because Allaah has warned against doing that. Allaah says in Soorat al-Nisaa’ (interpretation of the meaning):
“Allaah commands you as regards your children’s (inheritance): to the male, a portion equal to that of two females; if (there are) only daughters, two or more, their share is two-thirds of the inheritance; if only one, her share is a half. For parents, a sixth share of inheritance to each if the deceased left children; if no children, and the parents are the (only) heirs, the mother has a third; if the deceased left brothers or (sisters), the mother has a sixth. (The distribution in all cases is) after the payment of legacies he may have bequeathed or debts. You know not which of them, whether your parents or your children, are nearest to you in benefit; (these fixed shares) are ordained by Allaah. And Allaah is Ever All‑Knower, All‑Wise.
In that which your wives leave, your share is a half if they have no child; but if they leave a child, you get a fourth of that which they leave after payment of legacies that they may have bequeathed or debts. In that which you leave, their (your wives) share is a fourth if you leave no child; but if you leave a child, they get an eighth of that which you leave after payment of legacies that you may have bequeathed or debts. If the man or woman whose inheritance is in question has left neither ascendants nor descendants, but has left a brother or a sister, each one of the two gets a sixth; but if more than two, they share in a third, after payment of legacies he (or she) may have bequeathed or debts, so that no loss is caused (to anyone). This is a Commandment from Allaah; and Allaah is Ever All‑Knowing, Most‑Forbearing.
These are the limits (set by) Allaah (or ordainments as regards laws of inheritance), and whosoever obeys Allaah and His Messenger (Muhammad) will be admitted to Gardens under which rivers flow (in Paradise), to abide therein, and that will be the great success.
And whosoever disobeys Allaah and His Messenger (Muhammad), and transgresses His limits, He will cast him into the Fire, to abide therein; and he shall have a disgraceful torment”
And Allaah knows best.
Further reading: A 6-Step Guide to Making Your Will