Asim bin Amr al-Bajali narrates the following statement of Umayr, the freed slave of Sayyiduna Umar: Some people from Iraq came to Sayyiduna Umar (may Allah be pleased with him). Sayyiduna Umar (may Allah be pleased with him) asked: "What has brought you?" They said: "We have come to you to ask you about three things." Sayyiduna Umar (may Allah be pleased with him) said: "What are they?" They said: "A man's offering voluntary prayer in his house, what is it? How far is it permissible for a man to be intimate with his wife while she is menstruating? And we want to ask about the ritual bath for janabah." Sayyiduna Umar (may Allah be pleased with him) said: "Are you sorcerers?" They said: "No! By Allah, O Commander of the Believers, we are not sorcerers." Sayyiduna Umar (may Allah be pleased with him) said: "Then are you soothsayers?" They replied: "No!" Sayyiduna Umar (may Allah be pleased with him) said: "You have asked me about three things which, since I asked the Prophet (peace and blessings be upon him) about them, no one other than you has asked me about until now." Then Sayyiduna Umar (may Allah be pleased with him) said: "As for a man's offering voluntary prayer in his house, it is light, so illuminate your house as much as you can. As for the matter of the menstruating woman, what is above the waist-wrap is permissible for you, and what is below it is not permissible for you. As for the ritual bath for janabah, pour water with your right hand over your left hand, then put your hand into the vessel and wash your private parts and whatever has stained you, then perform ablution like the ablution for prayer, then pour water over your head three times, rubbing your head each time."
Abu Ya'la recorded it with this chain, and its narrators are thiqat (trustworthy); the narrators of Ahmad are likewise, except that it contains a person who is not named, so he is majhul (unknown).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الطهارة / 1468