Umar ibn Abdul-Aziz wrote to one of his workers, advising him to follow the path of the Companions:
There is no room to fall short of them and there is no room to go beyond them. Some people shortened the matter and fell short. Some people went above them and therefore went to extremes. They (the pious predecessors) were between that (those two extremes) upon a straight guidance."
[Recorded by Abu Dawud]