Does an intrinsic, connected increase (Ziyada Muttasilah) in the gifted item prevent the father's right to revoke the gift?

Primary text

The fourth condition is that there must not be an intrinsic, connected increase, such as fatness, growth, or the acquisition of a skill. Regarding increases, there are two narrations from Ahmad. One view, adopted by Al-Shafi'i, holds that the increase does not prevent revocation, as it is an increase in the gifted item, similar to increases before receipt or disconnected increases. The second view holds that it prevents revocation, which is the position of Abu Hanifa. This is because the increase is the property of the donee as an increment of his ownership, and it did not come to him from the father's side, so the father cannot revoke the original item. This prevents problems arising from shared ownership and fractional division. This is also compared to recovering the principal upon voiding a contract without a defect in the counter-value, like retrieving the dower upon dissolving a marriage or half of it upon divorce, or the seller revoking the sale due to the buyer's bankruptcy. The prohibition is valid for increases in essence (fatness, height), in attributes (learning a craft, writing, Quran, knowledge, conversion to Islam, or paying off a debt), according to Muhammad bin Al-Hasan. If the increase is recovery from illness or deafness, revocation is prevented, similar to other increases. If the increase or learning does not change the value or decreases it, it does not prevent revocation, as it is not a financial increase.