al-Aʿrāf 7:1

Alif-Lām-Mīm-Ṣād

This is one of the two disconnected-letter sequences in the Qurʾān made up of four letters (the other being al-Mr — al-Raʿd 13/1). And the sequence al-Mṣ occurs only here in the Qurʾān.

The record concerning the disconnected letters was set down in al-Baqara at 2/1 and in Ṭāhā at 20/1: what the letters mean is not known with certainty; explanations are transmitted, none of them carrying certainty. I rely on that treatment and do not repeat it here. Claims resting on the reckoning of letters and numbers are not used in this commentary (Method).

The one thing that belongs here is the placement of the sequence, and that is a countable datum:

In all five of these sūras the "Book" is named immediately after the disconnected letters. This is a verifiable pattern; I make no claim about what it means.