The Prophet (peace and blessings be upon him) said:
"Indeed, Allah Almighty brought me forth through (lawful) marriage, and He did not bring me forth through fornication (the path of indecency). (That is, my lineage is pure and rests upon lawful, Shari'ah-sanctioned marriage.)"
Hadith Referenceصحیح الجامع الصغیر / حرف الألف / 1703