Is a father's informing his children that a specific portion of land belongs to one of the children considered a bequest that is not included in the division of the inheritance?

If the father acknowledged during his lifetime, while in good health, that a part of the land belongs to his son, then this acknowledgment is valid, and that part belongs to the son and does not enter into the inheritance. However, if the acknowledgment was made during his death illness, it is an acknowledgment to an heir during death illness, and jurists have differed regarding its validity. If the father was not accused of bias towards the son, or if the heirs corroborated him, then the land belongs to the son and does not enter into the estate. If he was accused and the heirs did not corroborate him, then the entire land is divided according to Sharia law. In both cases, his acknowledgment is not considered a will.