It is narrated from Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) that one of his wives felt an aversion to men, so whenever he intended to be intimate with her, she would give menstruation as an excuse. Sayyiduna Umar (may Allah be pleased with him) thought that perhaps she was lying, so he had intercourse with her and found her truthful in what she had said. Then he came to the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) ordered him to give "one fifth of a dinar" in charity.
This hadith is hasan (good).
Through a second chain it is also narrated from Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) that he had a wife; then the narrator mentioned the same as the previous narration.
And the wording of Imam al-Harith's narration is that Sayyiduna Umar (may Allah be pleased with him) went to one of his slave-women, and she said: I am menstruating. But he had intercourse with her and found that she was indeed menstruating. When he mentioned this matter to the Prophet (peace and blessings be upon him), he (peace and blessings be upon him) said: "Yaghfirullahu ya Aba Hafs (May Allah forgive you, O Abu Hafs); give half a dinar in charity."
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب الحيض / 208
Hadith Gradingمحدثین:إسناده حسن
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :قال ابن حجر: حَدِيثٌ حَسَنٌ . » «أخرجه سنن الدارمي برقم: 1110، وأخرجه إتحاف الخيرة المهرة بزوائد المسانيد العشرة برقم: 736/1»