Narrated Asma bint Abu Bakr: My mother came to me during the lifetime of Allah’s Apostle and she was a pagan. I said to Allah’s Apostle (seeking his verdict), “My mother has come to me and she desires to receive a reward from me, shall I keep good relations with her?” The Prophet (peace be upon him) said, “Yes, keep good relation with her.”

Sahih Al-Bukhari – Book 47 Hadith 789