It shall be established for ever as the moon
Either Christ's seed, or throne, which comes to much the same sense; for by both are meant his church and people, his kingdom and interest in the world; the moon is as perpetual as the sun, and is used as elsewhere to signify the continuance of the people, church, and interest of Christ, ( Psalms 72:5 Psalms 72:7 ) , for though the moon has its spots, and is changeable, sometimes in the full, and sometimes in the decline, yet always is, and always continues, and ever will; and so though the people of God have their spots and imperfections, and are sometimes on the decline in the frames and dispositions of their minds, in the exercise of grace, in their spirituality, liveliness, and zeal, and in their walk and conversation in the church and world; yet they shall abide and persevere to the end; and though the church may be like the moon in the wane, be declining as to numbers, gifts, and graces, yet it shall continue and be established; it is sometimes indeed in a fluctuating state, and is not always in the same place, but is removed from one country to another; yet it always is somewhere, even though in the wilderness, and ere long will be established on the top of the mountains, and be no more a tabernacle that shall be taken down; see ( Psalms 48:8 ) ( 87:5 )
and as a faithful witness in heaven:
or "in the sky or cloud" F2; some understand this of the moon, others of both sun and moon; but it seems best to interpret it of something distinct from either, even of the rainbow, which though it does not always appear in the clouds, yet it has appeared at times, and does and will unto the end of the world; and be a faithful and an everlasting token and witness of the covenant of God made with all creatures, that he will no more destroy the world by a flood, ( Genesis 9:12 Genesis 9:13 Genesis 9:16 Genesis 9:17 ) , and is an emblem of the covenant of grace, and of the continuance, perpetuity, and immutability of it; see ( Isaiah 54:9 Isaiah 54:10 ) .
Selah. (See Gill on Psalms 3:2).