Sahih Muslim 1404
Sahih Muslim · Book 16: The Book of Marriage · Mut'ah Marriage: It was permitted then abrograted, then permitted then abrogated, and it will remain Forbidden until the day of resurrection
This hadith has been narrated on the authority of Isma'il with the same chain of transmitters (and the words are):
وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ ، حَدَّثَنَا وَكِيعٌ ، عَنْ إِسْمَاعِيلَ ، بِهَذَا الإِسْنَادِ قَالَ كُنَّا وَنَحْنُ شَبَابٌ فَقُلْنَا يَا رَسُولَ اللَّهِ أَلاَ نَسْتَخْصِي وَلَمْ يَقُلْ نَغْزُو .
" We were young, so we said: Allah's Messenger, should we not have ourselves castrated? But he (the narrator) did not say; We were on an expedition."