He said to them:

“O my people! Either you are better guided than the Companions of Muhammad, or else you are holding fast to a strand of misguidance.”

The underlying principle is this: acts of worship that God has legislated to recur at fixed times—so that they become regular Sunnahs and recognized seasons—already provide the servants with all they need. Whenever people establish an additional gathering that recurs habitually beyond those prescribed occasions, they are in effect setting up a rival to what God Himself has ordained. Such innovation carries many harmful consequences, some of which have already been pointed out. This differs from what an individual may do on his own, or what a particular group may do occasionally.

For that reason the Companions disliked designating the month of Rajab for fasting alone, because it came to resemble Ramadan. In the same vein ʿUmar, may Allah be pleased with him, ordered the tree to be cut down that people imagined to be the very tree under which the Companions pledged the Pledge of Ridwān, when he saw them flocking to it and praying there as though it were the Sacred Mosque or the Prophet’s Mosque. Likewise, when he observed them lingering at a spot where the Prophet, peace and blessings be upon him, had prayed and remaining there constantly, he forbade them, saying:

“Do you intend to turn the traces of your Prophets into places of worship?”—or words to that effect, may Allah be pleased with him.

In the same way, voluntary prayer—whether performed individually or in congregation—is lawful, provided that no group makes it into a fixed, habitual gathering