Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrated: The Prophet (peace and blessings be upon him) stayed at Khaybar for six months, and during that time he kept offering the Zuhr and Asr prayers together and the Maghrib and Isha prayers together.
Imam al-Tabarani recorded it in al-Mu'jam al-Awsat; its chain contains a narrator, Hafs bin Umar al-Juddi; Imam al-Dhahabi says: He is munkar al-hadith (his narrations are rejected).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 2976