It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him), in explaining the saying of Allah Almighty: "And to Him submit whoever is in the heavens and the earth, willingly and unwillingly" [Surah Al Imran: 83], said: "Those in the heavens are the angels; those on the earth are those who were born upon Islam; and 'unwillingly' refers to those who were brought from among the captives of the nations in chains and iron collars; they are led towards Paradise despite their unwillingness."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11425