There is no harm in interceding for one of the sons

Question: His Eminence the Shaykh / Abdullah ibn Abdulaziz ibn Baz, may Allah grant him understanding
Peace be upon you, and Allah’s mercy and blessings, and after that:
I am presenting this question to your Eminence, hoping for a written fatwa from you, may Allah preserve you and benefit the Muslims through you.
A man had a sum of money and wanted to buy a building with it, but the value of the building exceeded the amount he had. So he went to his father and asked him to go with him to two people whom Allah had enriched, to intercede with them on his behalf to complete the remaining amount as a gift. The father went with his son and interceded for him with them, and they agreed to gift him the remainder. In fact, the son was given the amount and bought the building. However, the father is now troubled by the doubt that he favored this son over his brothers by this action.
The question is: Has the father, by the aforementioned intercession, been unjust to his other children? And will the brothers share in the gift that the son obtained through his father? Please issue a ruling, may you be rewarded, and may Allah reward you with good.
And upon you be peace, and Allah’s mercy and blessings, and after that:
We do not know of any harm in the aforementioned intercession, and there is no harm on you or on him in that, if Allah wills; because what is forbidden is favoring one in giving, whereas interceding for you or for others is not harmful for him if it is in a permissible or prescribed matter; due to the generality of the evidence in this regard. May Allah guide them all.