Asma' bint Abu Bakr reported: My mother who was a polytheist came to me when he (the Holy Prophet) entered into treaty with, the Quraish (of Mecca). I inquired from the Messenger of Allah (ﷺ) saying: Messenger of Allah, there has come to me my mother and she is inclined; should I (in this state of her mind) show her kindness? He said: Yes, treat her kindly.
Source: sunnah.com
Other translations
Arabic
وَحَدَّثَنَا أَبُو كُرَيْبٍ، مُحَمَّدُ بْنُ الْعَلاَءِ حَدَّثَنَا أَبُو أُسَامَةَ، عَنْ هِشَامٍ، عَنْ أَبِيهِ، عَنْ أَسْمَاءَ بِنْتِ أَبِي بَكْرٍ، قَالَتْ قَدِمَتْ عَلَىَّ أُمِّي وَهِيَ مُشْرِكَةٌ فِي عَهْدِ قُرَيْشٍ إِذْ عَاهَدَهُمْ فَاسْتَفْتَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم فَقُلْتُ يَا رَسُولَ اللَّهِ قَدِمَتْ عَلَىَّ أُمِّي وَهْىَ رَاغِبَةٌ أَفَأَصِلُ أُمِّي قَالَ " نَعَمْ صِلِي أُمَّكِ " .
sunnah.com