Sunan an-Nasa'i, Hadith 3858 ⓘ
It was narrated from Al-Hasan that he disliked to hire a man without telling him what his wages would be.
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.
also referenced under: Book 35b, Hadith 2 (In-Book) & Volume 4, Book 35, Hadith 3889 (DarusSalam)