The great trumpet had not been blown, the jubilee had not come, the chains had not been knocked off, the shackles not loosed, and the prison-gates not thrown open; they could not therefore worship God freely, fully and calmly, with liberty of access and freedom of spirit. But where do they worship Him? “In the holy mount.” The holy mount we may understand to signify spiritually Mount Zion, the place where Jesus sits in glory.
“And it shall come to pass in that day, that the great trumpet shall be blown, and they shall come which were ready to perish in the land of Assyria, and the outcasts in the land of Egypt, and shall worship the Lord in the holy mount at Jerusalem.” — Isaiah 27:13
Called by the sounding of the great trumpet, the perishing and outcasts come to the Lord. And what do they do when they come? Do they trifle with sin, mock God, and abuse His grace? We read not so. They “worship the Lord in the holy mount at Jerusalem.” They worship Him in spirit and in truth; they worship Him in the beauty of holiness. With purified hearts, purged consciences, and spiritual affections, they fall down before Him, and their souls are impressed with a sense of the greatness of His love.