Not graded
Mishkat al-Masabih 3340
عَن مَالِكٍ قَالَ: بَلَغَنِي أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ يَأْمُرُ بِاسْتِبْرَاءِ الْإِمَاءِ بِحَيْضَةٍ إِنْ كَانَتْ مِمَّنْ تَحِيضُ وَثَلَاثَةِ أَشْهُرٍ إِنْ كَانَت مِمَّن تحيض وَينْهى عَن سقِِي مَاء الْغَيْر
Malik said he heard that God's Messenger used to command that no intercourse be had with slave women till they had had a menstrual period if they were of the number who had such periods, or till three months had passed in the case of those who did not, and forbid watering another man's water. Razin transmitted.
Cited in Mishkat al-Masabih (No. 3340).