ENOfficial
It was narrated from Al-Hasan that he disliked to hire a man without telling him what his wages would be.
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنَا مُحَمَّدٌ، قَالَ أَنْبَأَنَا حِبَّانُ، قَالَ أَنْبَأَنَا عَبْدُ اللَّهِ، عَنْ حَمَّادِ بْنِ سَلَمَةَ، عَنْ يُونُسَ، عَنِ الْحَسَنِ، أَنَّهُ كَرِهَ أَنْ يَسْتَأْجِرَ الرَّجُلَ، حَتَّى يُعْلِمَهُ أَجْرَهُ.
sunnah.com