Adam Clarke's Commentary on the Bible - Psalms 99:3
Let them praise thy great and terrible name - Let them confess thee to be great and terrible: let them tremble before thee. For it is holy - הוא קדוש kadosh hu . As this not only ends this verse but the fifth also, and in effect the ninth, it seems to be a species of chorus which was sung in a very solemn manner at the conclusion of each of these parts. His holiness - the immaculate purity of his nature, was the reason why he should be exalted, praised, and worshipped. read more
Adam Clarke's Commentary on the Bible - Psalms 99:2
The Lord is great in Zion - It is among his own worshippers that he has manifested his power and glory in an especial manner. There he is known, and there he is worthily magnified. read more