Mukhtasar Muslim (Abridged) 1121 — Prophet’s letters to kings inviting

It is narrated from Sayyiduna Anas (may Allah be pleased with him) that the Noble Prophet Muhammad (peace and blessings be upon him) wrote to Kisra, Caesar, Najashi, and every ruler, inviting them towards Allah Almighty. And this Najashi was not the one upon whom the Prophet (peace and blessings be upon him) performed the funeral prayer.