The first dawn appears approximately half an hour before the second dawn; then it fades away and the sky becomes dark again, after which the second dawn emerges. The scholars have said that there are three differences between them:

First: the second dawn spreads horizontally, whereas the first extends vertically toward the middle of the sky.

Second: no darkness follows the second dawn, whereas the first disappears and the sky becomes dark after it.

Third: the second dawn is connected to the horizon, while the first dawn is not. That is, the second dawn is visible along the surface of the earth, whereas there is darkness between the first dawn and the lower sky. (1)

His statement, “from the second dawn,” means: not from the Fajr prayer.

A weak hadith has been cited as evidence for this: “When dawn rises, there is no prayer except the two rak‘ahs of Fajr.” (2) Here, “no” is a negating particle. The basic meaning of negation is the negation of existence; then the negation of validity; then the negation of completeness. That is, when the texts state, “No prayer …,” “No ablution …,” or “No fasting …,” the basic meaning is the negation of existence. If the thing does exist in a manner that makes its existence impossible to negate, the negation is understood as a negation of validity. Thus, this negation becomes a negation of validity, because that which is not valid in the Sacred Law