Answer (Imam Wahbah az-Zuḥaylī):
Ḥaqīqah is witnessing the secrets of Lordship, and it is derived from the Sharīʿah. Thus, the Sharīʿah is the foundation and the Ḥaqīqah is the branch that is extracted from the Sharīʿah. The Ḥaqīqah is knowledge of the attributes of the heart, and the people of Ḥaqīqah have a strong concern and interest in them. The people of Sharīʿah are more concerned with the decisive rulings of the Revealed Law. They differ in terms of interest and concern for knowledge of the attributes of the heart, and in reality that is not a difference of opinion between the two groups.
[Translated from Fatāwā Muʿāṣirah (Damascus: Dār al-Fikr, 1427/2006), p.270-271]