Qatadah regarded learning the lunar stations as disliked, and Ibn ʿUyaynah did not permit it. Harb transmitted this view from both of them, whereas Ahmad and Ishaq considered the study of the stations permissible.

Biographical notes:
1- Ibn ʿUyaynah: Sufyan ibn ʿUyaynah.
2- Harb: Harb al-Karmani, one of Ahmad’s foremost disciples.
3- Ahmad: Imam Ahmad ibn Hanbal.
4- Ishaq: Ishaq ibn Rahawayh.

The lunar stations are the positions the moon occupies each night—twenty-eight in all—and knowledge of them is called ʿilm al-tasir (astronomical observation for determining directions and times).

Purpose of this passage: to set out the scholarly disagreement over learning the lunar stations, a branch of ʿilm al-tasir whose aims are to locate the qiblah, determine the prayer times, and identify the seasons. If the scholars differed over this harmless discipline merely as a precaution—so that it would not become a gateway to what is forbidden—how much more emphatically would they forbid the study of ʿilm al-taʾthir, which concerns the alleged influence of the stars and is sheer misguidance and danger.