Is the performance of a vowed obligation by a guardian for the deceased mandatory or recommended?

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The majority of scholars hold that the performance of the deceased's vows by the guardian is not obligatory unless the vow constitutes a debt linked to the estate (property left behind). The command of the Prophet, peace be upon him, concerning fulfilling a vow (like fasting) is understood to be an injunction for recommendation and desirability, derived from the context in which the Prophet likened it to a debt, and the debt of the heir is not obligatory unless the deceased left an estate for repayment. Moreover, the response of the Prophet to the questioner implied permission or fulfillment, depending on the inquiry's context, which in this case concerned fulfillment (Ijza').