Musannaf Ibn Abi Shaybah 40670 — reports on Siffin

Ata bin al-Sa'ib said: Several people told me that a judge from Sham once came to Sayyiduna Umar (may Allah be pleased with him) and said: "O Commander of the Believers, I have seen a dream that has frightened me. I saw the sun and the moon fighting one another, with the stars divided in half, half with each." Sayyiduna Umar asked him: "With which of them were you?" He said: "I was with the moon, fighting against the sun." Sayyiduna Umar recited this verse of the Qur'an: "And We made the night and the day two signs, then We erased the sign of the night and made the sign of the day visible" [Al-Isra: 12]. Then he said: "Go away; I will not give you any post from now on."