Amrah bint Ubaydullah bin Abdullah bin Abbas narrated from her father, from Sayyiduna Ibn Abbas (may Allah be pleased with them both), that the Prophet (peace and blessings be upon him) said: "Whoever frees a believer in this world, Allah will free him from Hell for every limb of his."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 10595