200 FAQ On Muslims Belief by Hafiz Ibn Ahmed Al Hakami

A--- First: it nullifies the whole act of worship such as adding a third Rak'ah to the Fajr Prayer, a fourth one to the Maghrib, or a fifth to the Zuhr Prayer. Or, such as decreasing a Rak' ah thereof.

Second: it does not nullify the act of worship though it is (Innovation)

itself is basically nullified. Such as the one who adds a fourth time of wash to the organs to be washed in Ablution. The Prophet (Peace be upon him) did not say it is nullified, but said: "Whosoever adds to this, he certainly did badly, transgressed and did (something) wrong." (Abu Dawud and Ibn Majah)