Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) forbade hiring a labourer until his wage has been made clear to him.
Ahmad recorded it, and al-Nasa'i (may Allah have mercy on him) recorded it as a "mawquf" narration; the narrators of Ahmad are the narrators of the Sahih, except that, in my view, Ibrahim al-Nakha'i did not hear from Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب البيوع / 6454
Hadith Gradingمحدثین:إسناده منقطع
Hadith Takhrij«اخرجه احمد فى المسند (68/3) ، أخرجه مسند أحمد برقم: 11171، 11279»