Does zakat become obligatory on real estate purchased by a merchant to endow it for the poor, if a year passes while it is vacant?

If a man buys real estate with the intention of it being an endowment (waqf), not for trade, then there is no zakat (definition) on it. This is because it is not considered a trade commodity. Rather, it is in the same category as something prepared for personal use (qinyah), based on the Prophet's (peace be upon him) saying: "There is no sadaqah (definition) (zakat) on a Muslim for his slave or his horse." Furthermore, wealth endowed for the poor is not subject to zakat.