Is zakat obligatory again on the entire amount after selling the cement booking receipt, which was initially intended for trade then for personal use, or only on the profit, after zakat had been previously paid on it while it was still with the factory?

The zakat on the amount paid to the factory owners is not obligatory, as the buyer has already taken possession of the cement. If the buyer's intention changes from trading the cement to using it for construction, then no zakat is due on it. Selling the aforementioned receipt is considered selling a debt, which is permissible under certain conditions. The price resulting from the sale of the debt is subject to the passage of a full year (hawl), and zakat is paid on it at the completion of the year if it reaches the nisab (minimum threshold) on its own or when combined with other cash or trade goods.