How do we reconcile the saying of the Messenger (peace and blessings be upon him), “Every innovation is misguidance,” with the saying of 'Umar (may Allah be pleased with him), “What a good innovation this is”?

Question:
The saying of the Messenger (peace and blessings be upon him), “Every innovation is misguidance,” was reported from 'Umar (may Allah be pleased with him and grant him contentment) that he said regarding the tarawih prayer when he gathered the people: “What a good innovation this is.” He asks: How is the answer to this?

Answer:
It is a linguistic innovation, my brother. That is, a legal innovation. 'Umar could not have said that this is a legal innovation. It is a linguistic innovation: something the people had not been accustomed to. 'Umar (may Allah be pleased with him) gathered them behind a single imam, whereas they had been praying separately. So he said, “What a good innovation this is,” meaning that he gathered them behind a single imam for the tarawih prayer in Ramadan, behind Ubayy ibn Ka'b. Yes, there is a linguistic innovation here, meaning something the people had not been accustomed to. So 'Umar introduced this practice and gathered them behind Ubayy ibn Ka'b as a single imam. Yes.