The Prophet ﷺ said: “Free the captive, feed the hungry, and visit the sick.” (al-Bukhārī). Today this includes helping release those jailed over debts by paying or negotiating them. And: “Whoever frees a believing slave, Allah frees a limb of his from the Fire for each limb of the freed one.” (al-Bukhārī).
العربية: عن أبي موسى رضي الله عنه قال: قال رسول الله ﷺ: «فُكّوا العانيَ — يعني الأسير — وأطعِموا الجائع، وعودوا المريض». (البخاري).
Help free those unjustly detained or jailed for debt — a great, neglected Sunnah.