Can someone please verify these quotes which are alleged to be taken from Chapters on Marriage and Divorce. It seems that from these quotes, there is no minimum age for having intercourse with your female slave.
I heard Aḥmad asked about an istībrāʾ for a girl of ten, and he thought there should be one. I heard Aḥmad say, “A girl of ten years of age may become pregnant.” Someone said to Aḥmad while I was listening, “Even if she is too young to menstruate (ṣaghīra)?” He said, “If she is [very] young, that is, if she is still suckling, then waiting an istibrāʾ has no legal consequences.”
Chapters on Marriage and Divorce Chapter 2 (Abu Dawud) §59-§61
I said, “What about a man who buys a female slave not old enough to menstruate?” He said, “He abstains from having sexual intercourse with her for three months.” ... I said to my father, “May he have intimate contact other than that of sexual intercourse with his prepubescent female slave?” He said, “Not until he has abstained from having sexual intercourse with her for three months.” ... I asked my father about a man who buys a female slave who is too young to menstruate. “How long should he refrain from having sexual intercourse with her?” He said, “For three months.” I said to my father, “What about intimate contact other than that of intercourse? Can he, for example, touch or kiss her?” He said, “I prefer him not to do that. He should wait an istibrāʾ, for I cannot be certain that if he does touch or kiss her and she is pregnant, he will not do so in an unlawful manner.”
Chapters on Marriage and Divorce Chapter 3 (Abdullah) §138-§139
I said, “Sufyān said, and he was one of those among the scholars (ahl al-ʿilm) whose opinion was sought, that when a man bought a young female slave, one considered too young for sexual intercourse, that it was not necessary for her to wait an ʿidda. He said, ‘What I prefer when a man buys a female slave too young for intercourse is that her new owner should neither kiss her nor have sexual contact with her, until he has waited a period of istibrāʾ on her behalf, in accordance with the sunna [concerning female slaves].’” Aḥmad said, “What Sufyān said is excellent.” Isḥāq said, “There is no harm in his kissing her and having sexual contact with her, because she is among those whom one need not fear having to return to her previous owner because of pregnancy.
Chapters on Marriage and Divorce Chapter 3 (al-Kawsi) §224