Hadithcore
Sahih Muslim, 715 ac
sahih

This tradition has been reported through anothee chain. 'Abdurahman, one of the sub-narrators, said "I do not know if it in the hadith or not", meaning (the words) "doubting their fidelity and spying into their lapses."

وَحَدَّثَنِيهِ مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا عَبْدُ الرَّحْمَنِ، حَدَّثَنَا سُفْيَانُ، بِهَذَا الإِسْنَادِ قَالَ عَبْدُ الرَّحْمَنِ قَالَ سُفْيَانُ لاَ أَدْرِي هَذَا فِي الْحَدِيثِ أَمْ لاَ ‏.‏ يَعْنِي أَنْ يَتَخَوَّنَهُمْ أَوْ يَلْتَمِسَ عَثَرَاتِهِمْ ‏.‏

References2 variants
In-Book Reference
Book 33, Hadith 265
USC-MSA web (English) reference
Book 20, Hadith 4730 (deprecated numbering scheme)