Sahih Adab al-Mufrad

952/1251 (Authentic chain, mawquf and mursal) from Al-Hasan [هو البصري] who said: "Are you not amazed at this? – meaning: Malik ibn Al-Mundhir – he went to some elders from the people of (Kaskar) who had accepted Islam, so he examined them and ordered that they be circumcised, and it was winter, and I was informed that some of them died. Indeed, the Roman and the Abyssinian accepted Islam with the Messenger of Allah, peace and blessings be upon him, and nothing was examined about them." (1).