Sahih (Sahih Muslim)
وَحَدَّثَنَاهُ ابْنُ الْمُثَنَّى، حَدَّثَنَا ابْنُ أَبِي عَدِيٍّ، عَنْ سَعِيدٍ، عَنْ قَتَادَةَ، بِهَذَا الإِسْنَادِ وَقَالَ " أَكْثَرَ مِنْ ثَلاَثٍ إِلاَّ مَعَ ذِي مَحْرَمٍ " .
This hadith has been narrated on the authority of Qatada with the same chain of transmitters and he said:" More than three (days) except in the company of a Mahram