Is the consent of the guarantor necessary for the validity of the guarantee?
Chapter on Guarantee (Daman)
Al-Mughni
Book of Assignment (Transfer of Debt)
Primary text
The consent of the guarantor is necessary; if the guarantor is coerced into the guarantee, the contract is invalid. The consent of the principal debtor is not required for validity; this is an established position for which no known disagreement exists, because settling a debt on behalf of someone without their permission or consent is valid, and guarantee is analogous to this.
Supporting text
Abu Hanifa and Muhammad require the consent of the beneficiary (Madmun lahu) for the guarantee to be valid, arguing that establishing a financial right for a person requires their consent or the consent of their representative, similar to sale and purchase. Evidence supporting the main position is the action of Abu Qatada guaranteeing without the consent of the debtor, which the Prophet (peace be upon him) permitted, and a similar report from Ali (may Allah be pleased with him).