Must a killer be imprisoned when execution of retribution (Qisas) must be delayed?

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The killer must be imprisoned until the victim's son reaches maturity, the insane person regains sanity, or the absent party returns, whenever the implementation of retribution is necessarily delayed. This practice is evidenced by the imprisonment of Hudbah ibn Khashram by Mu'awiyah pending the victim's son reaching maturity during the era of the Companions, an act that received no objection. Al-Hasan, Al-Husayn, and Sa'id ibn al-'As offered seven blood prices (diyah) to the victim's son, which he refused. The justification for this imprisonment, unlike the case of someone imprisoned for debt inability (I'sar), is that releasing the killer would lead to the loss of the right (Qisas), as escape is feared. Furthermore, debt payment is not obligatory during inability to pay, whereas retribution here is obligatory, only its execution is temporarily obstructed. Moreover, the imprisoned person's capacity for earning is not the primary concern, as releasing him causes the right itself to be lost, unlike the debtor whose earning capacity is hindered by imprisonment, causing harm on two fronts. Finally, since the killer has earned execution, forfeiting his benefit (imprisonment) is permissible to secure the forfeiture of his life, which is the primary right.