It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: It is not permissible to sever relations for more than three days.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 8919
Hadith Gradingحکم دارالسلام:حديث صحيح، وهذا إسناد قوي، م: 2562