Sayyidah Asma' bint Abi Bakr (may Allah be pleased with her) said: My mother came to me, desiring (my kindness), during the period of the treaty with Quraysh. I asked the Messenger of Allah (peace and blessings be upon him) about maintaining ties with her, and he (peace and blessings be upon him) said: "Yes, maintain ties with her."
Imam al-Shafi'i (may Allah have mercy on him) said: The Messenger of Allah (peace and blessings be upon him) gave permission to Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) to clothe a polytheist relative of his in Makkah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18331