Ali bin Husayn (may Allah have mercy on him) said to a caretaker of his who had harvested his date palms at night: Do you not know that the Messenger of Allah (peace and blessings be upon him) forbade cutting fruit at night and plucking fruit at night? Or he said: and harvesting at night. Sufyan (may Allah have mercy on him) said: It is said: (it should be) so that it is done in the daytime and the poor are present.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / 19200
Sufyan narrated it with the same meaning, but did not mention the plucking of dates and the harvesting. Sufyan said: They asked Ja'far about sacrificing at night, and he said: No. Sufyan said: This (prohibition) concerns the situation of the poor.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / 19201