“However, the Taz stipulates that the person must have intended to use the ma’aser money when he purchased the aliyah,” continued Rabbi Dayan. “If the person did not think at the time of the aliyah to use ma’aser money – and does not regularly do so – he may not use ma’aser money for this purpose. In this case, the pledge becomes like an obligatory debt, and a person may certainly not pay his outstanding debts with ma’aser money.”
“Furthermore,” concluded Rabbi Dayan, “some maintain that one can only use ma’aser money if the aliyah would not have been bought otherwise or only for the amount added over the previous bidder. However, others reject these distinctions, especially if the previous bidder would also likely pay from his ma’aser kesafim.” (See Hilchos Ma’aser Kesafim, 14:29-32)