Ibn Hajar Al-Haythami said:
“In ‘Umar’s saying regarding the tarawee prayers, ‘This is a good bid’ah,‘ he meant the linguistic meaning of bid’ah, which is to do something that was not being done, similar to what Allaah says:
“I did not bring a bid’ah (something new) among the messengers.” [46:9].
This does not indicate a bid’ah in the shar’ee sense, because a bid’ah would be an act of misguidance, as was indicated by the Messenger (saw).
Scholars who classify the bid’ahs into good and bad only intend the linguistic meaning of bid’ahs; and those who say that every bid’ah is a misguidance mean the bid’ah in the Shar’ee sense.”
[Al-Ibdaa’ Fee Madaarr Il-Ibtidaa’]