Sunan an-Nasai 18603
In-book no 3867أَخْبَرَنَا مُحَمَّدٌ، قَالَ أَنْبَأَنَا حِبَّانُ، قَالَ أَنْبَأَنَا عَبْدُ اللَّهِ، عَنْ حَمَّادِ بْنِ سَلَمَةَ، عَنْ يُونُسَ، عَنِ الْحَسَنِ، أَنَّهُ كَرِهَ أَنْ يَسْتَأْجِرَ الرَّجُلَ، حَتَّى يُعْلِمَهُ أَجْرَهُ.
It was narrated from Al-Hasan that he disliked to hire a man without telling him what his wages would be.