He was asked:

About someone who washes his limbs more than five times and, when he comes to the mosque, spreads his prayer mat beneath his feet—and so on to the end of the question.

He replied:

The obsessive doubts concerning purification that he describes—such as washing a limb more than three times, refusing to pray on the mosque’s mats, and similar practices—are likewise religious innovation and misguidance, by the consensus of the Muslims. Such conduct is neither recommended, nor an act of obedience, nor a means of drawing near to Allah. Anyone who does this as an act of worship and obedience must be told to desist. If he refuses, he is to be disciplined for it.

Umar, may Allah be pleased with him, used to discipline people for praying after the afternoon prayer, even though some people did so because it was reported that the Prophet, may Allah bless him and grant him peace, had done so and maintained this practice. However, this was specific to him, may Allah bless him and grant him peace, and:

“The Prophet, may Allah bless him and grant him peace, had forbidden prayer after the afternoon prayer until sunset, and after the dawn prayer until sunrise.”

For this reason, Umar used to beat anyone who performed this prayer. It is therefore all the more fitting and warranted to beat those who introduce these innovations into purification and prayer, since these are blameworthy innovations by the consensus of the Muslims. Allah knows best.