‏النكاح : Hadeeth No:3374 Abu Sa'id al-Khudri (Allaah be pleased with him) (was asked if he had heard it himself), to which he said: Yes. (I heard) Allaah's Prophet (sallAllaahu alayhi wa sallam) as saying: There is no harm if you do not practise it, for it (the birth of the child) is something ordained (by Allaah)....

‏الجنة وصفة نعيمها وأهلها‏ : Hadeeth No:6879 This hadith has been transmitted on the authority of A'mash but with a slight variation of wording....