Hadith: If any of you has sexual intercourse with his wife and then wished to have intercourse again, then let him perform ablution between the two times

عن أبي سعيد الخُدْرِي رضي الله عنه مرفوعاً: «إذا أَتَى أحَدُكُم أهله ثم أرَاد أن يَعود فَلْيَتَوَضَّأْ بينهما وضُوءًا». وفي رواية الحاكم: «فإنه أَنْشَطُ لِلْعَوْد».
[صحيح] - [رواه مسلم، والرواية الثانية عند الحاكم]

Abu Sa‘īd al-Khudri (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "If any of you has sexual intercourse with his wife and then wished to have intercourse again, then let him perform ablution between the two times." The narration of Al-Hākim added: "as that will provide him with more energy for the second time."
Sahih/Authentic. - [Al-Haakim]

Explanation

This Hadīth clarifies the prophetic guidance concerning the one who wants to repeat sexual intercourse with his wife. The Prophet (may Allah's peace and blessings be upon him) said: "If any of you has sexual intercourse with his wife and then wished to do that again", i.e. have intercourse again for a second and third time. The prophetic guidance is represented in his statement: "then let him perform ablution between the two times", meaning that after having intercourse for the first time and before the second time. What is intended by ablution here is the ablution performed for prayer, because when "ablution" is used in the general sense, then the basic rule is that it refers to the Shariah-approved ablution. It was explicitly mentioned in the narration of Ibn Khuzaymah and Al-Bayhaqi: "then make ablution like the ablution you make for prayer". This ablution – between instances of intercourse – is recommended.