(Al-Qalam) 68 : 17
إِنَّا بَلَوْنَاهُمْ كَمَا بَلَوْنَا أَصْحَابَ الْجَنَّةِ إِذْ أَقْسَمُوا لَيَصْرِمُنَّهَا مُصْبِحِينَ
Indeed We will test them just like We tested the owners of a garden; when they swore that we would complete its harvesting in the early morning.
The owners of the gardens are swearing that they would complete the harvesting of the crops in their garden in the next early morning by themselves so that they can avoid the poor labourers presenting in the garden and giving wage and welfare tax for them. See explanation 2: 266; 6: 141; and 18: 32-44.