Sahih Muslim 827 h
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."
وَحَدَّثَنَاهُ ابْنُ الْمُثَنَّى، حَدَّثَنَا ابْنُ أَبِي عَدِيٍّ، عَنْ سَعِيدٍ، عَنْ قَتَادَةَ، بِهَذَا الإِسْنَادِ وَقَالَ ‏
"‏ أَكْثَرَ مِنْ ثَلاَثٍ إِلاَّ مَعَ ذِي مَحْرَمٍ ‏"‏ ‏.‏