The rule for one who finds his father enslaved in the pre-Islamic era

I asked Abu Abdullah (asws) about a man whose father had been made a captive in the era of Ignorance, so he never knew that he was a son whose father was made a captive in the era of ignorance until after he had been born a slave in Al-Islam and had been freed’. So he (asws) said: ‘His lineage is to his enslaved father in Al-Islam, then he would be counted from the tribe which his father was enslaved in, that he was known to be from them, and he will inherit from them and they will inherit from him’.