The Prophet ﷺ said to him, "When you arrive home at night, do not go in to your wife until the woman whose husband has been away has groomed herself and the disheveled one has combed her hair."He continued, "The Messenger of Allah ﷺ said, 'When you go in to her, then conduct yourself wisely, conduct yourself wisely.'"
حدثنا محمد بن جعفر حدثنا شعبة عن سيار عن الشعبي
أن النبي ﷺ قال له إذا دخلت ليلا فلا تدخل على أهلك حتى تستحد المغيبة وتمتشط الشعثة قال وقال رسول الله ﷺ إذا دخلت فعليك الكيس والكيس
Its isnad is sahih. It is found in Bukhari 9/341, no. 5245, in Fath al-Bari, in the book of marriage, chapter on seeking children, and in Muslim 3/1522, no. 715, and in all the Sahihs. It has already preceded in similar form.The meaning of "you must be shrewd, be shrewd" is intercourse, which he referred to euphemistically.