Is the concluded contract by which the father acquired ownership of the land, and which was named a sale contract and assigned a price to the land, even though the paid price is symbolic and much less than what is recorded in the contract, considered valid from a Sharia perspective, and is the father considered to have committed a sin from a Sharia perspective?

Possession and statute of limitations do not constitute a legitimate reason for the transfer of land ownership, unless accompanied by a verbal or constructive waiver. The sisters' silence about their shares in the land for twenty years, if it was of their own free will and without impediment, is considered a constructive waiver and an implicit endorsement of their brother's gift, especially if they were adult, sane, and mature. If their silence was due to an acceptable excuse, such as coercion, fear, or shyness, then their right is not forfeited by the statute of limitations. The sisters' agreement to sign a fictitious contract to document land ownership, if it was with their knowledge and consent, is considered an implicit acknowledgment of the previous waiver. Accordingly, if the implicit acknowledgment of the sisters' waiver is proven, then there is no sharia impediment to writing the fictitious contract to document the current ownership, and rewarding them later as a gift of recompense. However, if the constructive waiver is nullified due to the lack of its conditions, then the brother is only entitled to his share, and he must return the sisters' rights.