It was narrated from Maimunah bint Sa`d, the freed slave woman of the Prophet (ﷺ) that :
the Messenger of Allah (ﷺ) was asked about illegitimate children. He said: "Two sandals in which I wage Jihad are better than freeing an illegitimate child." (JA)
English reference (JA): Vol. 3, Book 19, Hadith 2531 (JA)
Arabic reference (JA): Book 19, Hadith 2628 (JA)