Al-Kāfi - Volume 5 > Detestability of Using the Labor of a Worker before Agreeing on Wages and Delay Payment of His Wages
Hadith #2

2- عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ ابْنِ أَبِي عُمَيْرٍ عَنْ هِشَامِ بْنِ الْحَكَمِ عَنْ أَبِي عَبْدِ اللهِ (عَلَيْهِ السَّلام) فِي الْحَمَّالِ وَالأجِيرِ قَالَ لا يَجِفُّ عَرَقُهُ حَتَّى تُعْطِيَهُ أُجْرَتَهُ.

2. Ali ibn Ibrahim has narrated from his father from ibn abu ‘Umayr from Hisham ibn al-Hakam who has said the following: “About the case of porters and a man working for hire, abu ‘Abd Allah, ‘Alayhi al-Salam, has said, ‘You must pay him before his perspiration dries up.’”