Tafsir of Al-Mursalat 77:30

"Depart," meaning specifically, so it is not a repetition of the first [command]. It is said that it is a repetition, but it is qualified by His saying, "to a shadow," which is the shadow of the smoke of Hell, as stated by the majority of exegetes. Thus, it is like His saying: "And a shadow of black smoke" (Al-Waqi'ah: 43). In this, there is a mocking metaphor.

Ruways narrated from Ya'qub: "Departed" (inṭalaqū) in the past tense form, which is an explanatory resumption, as if it were asked: "What happened after the command?" So it was said: "They departed to a shadow of three branches." It is branched because of its magnitude, having three branches as is the nature of great smoke; you see it separating like locks of hair.

In some traditions, a tongue of fire emerges and surrounds the disbelievers like a pavilion, and its smoke branches into three parts, shading them until their reckoning is finished, while the believers are in the shadow of the Throne.

Regarding the specificity of the number three, it is said: Because the veil of the soul from the lights of holiness [consists of three]: the sensory, the imaginary, and the rational. Or because that which leads to this punishment is the satanic illusory power residing in the brain, the bestial irascible power to the right of the heart, and the animalistic appetitive power to its left. Therefore, it is said that one branch stands above the disbeliever, one to his right, and one to his left.

It is also said: Because their denial of the punishment entails the denial of Allah the Almighty and the denial of His Messenger (may Allah bless him and grant him peace), thus there are three denials. Some considered the denial of the punishment as the root, and the three branches as the two mentioned denials plus the denial of sound reason; so contemplate this.

According to Ibn Abbas, this is said to the worshippers of the cross; for while the believers are in the shadow of Allah the Almighty, they are in the shadow of their object of worship, which is the cross that has three branches.