Authoritatively synonyms

This was the only authoritatively prescribed fast known to Tertullian (De jejunio, 2, 13, 14; De oratione, 18).

With the growth of the Oxford Movement in the English Church, the practice of observing Lent was revived; and, though no rules for fasting are authoritatively laid down, the duty of abstinence is now very generally inculcated by bishops and clergy, either as a discipline or as an exercise in self-denial.

Yet later the co p e seems to have been authoritatively proscribed with the rest.

But the Protestant casuist never pretended to speak authoritatively; all he did was to give his reasons, and leave the decision to the conscience of his readers.