"Why do you do that?" We said: "A man may have a wife, and he has intercourse with her, but he does not want her to get pregnant, or he may have a concubine, and he has intercourse with her, but he does not want her to get pregnant." He said: "It does not make any difference if you do that, for it is the matter of Al-Qadr."
Sunan an-Nasa'i Book 26, Hadith 132
← Previous Hadith "I was thinking of forbidding Ghilah until I remembered that it is done by the Persians and Romans" -(one of the narrators) Ishaq said: "(They) do that -and it does not harm their children."

Sunan an-Nasa'i Book 26, Hadith 131 Next Hadith → "My wife is breast-feeding and I do not want her to get pregnant." The Prophet said: "What has been decreed in the womb will come to be."

Sunan an-Nasa'i Book 26, Hadith 133