Abu Hasan, the freed slave of Abdullah bin al-Harith, who was among the early freed slaves of Quraysh and among their people of knowledge and righteousness, heard a woman saying to Abdullah bin Nawfal: I am obliged to free a slave; tell me about this. Abdullah bin Nawfal said: "You will not be discharged of the obligation by freeing a child born of fornication." Ibn Nawfal said: I heard Sayyiduna Umar (may Allah be pleased with him) saying: "That I give a pair of sandals in the path of Allah is dearer to me than that I free a child born of fornication."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الأيمان / 20005