Psalms 81:3 - Coke's Commentary on the Holy Bible

Blow up the trumpet, &c.— Blow up the trumpet on the first day of the month, on the new moon, on the day of our feast. The feast of the new moon was always proclaimed by the sound of trumpets. The fixing the time of the new moon, for want of astronomical tables, was done in the following manner: the first persons who observed, or thought they observed, the new moon, were to repair immediately to the grand council to give notice of it. Inquiry was then made into the credibility of the informers, and, secondly, whether their information agreed with such computations as they were then able to make. After which the president proclaimed the new moon by saying מקדשׁ mekaddesh; i.e. it is consecrated: this word was twice repeated aloud by the people; after which it was ordered to be proclaimed every where by the sound of the trumpet. See Univ. Hist. vol. i 2: p. 33. 8vo.