Lord, when thy hand is lifted up - This is an explanation of the sentiment expressed in the former verse. The lifting up of the hand here refers, doubtless, to the manifestations of the majesty and goodness of the Lord.
They will not see - They are blind to all the exhibitions of power, mercy, and goodness.
But they shall see - They shall yet be brought to recognize thy hand. They shall see thy favor toward thy children, and thy judgment on thy foes. The divine dealings will be such that they shall be constrained to recognize him, and to acknowledge his existence and perfections.
And be ashamed - Be confounded because they did not sooner recognize the divine goodness.
For their envy at thy people - The word ‘their’ is not in the Hebrew, and the sense is, that they shall see the zeal of Yahweh in behalf of his people, and shall be ashamed that they did not sooner recognize his hand. The word rendered ‘envy’ (קנאה qin'âh) may mean envy Ecclesiastes 4:4; Ecclesiastes 9:6, but it more properly and frequently means zeal, ardor, 2 Kings 10:16; Isaiah 9:6).
Yea, the fire of thine enemies shall devour them - Or rather, ‘Yea, the fire in regard to thy enemies shall devour them.’ The sense is, that when his people were delivered, his foes would be destroyed; his zeal for his people would also be connected with indignation against his foes. The deliverance of his people from Babylon, and the commencement of the downfall of that city, were simultaneous, and the cause was the same.