One command, two kinds of stopping.
Most quotations of the verse stop at the comma. Matthew Henry did not, and the reading that results is one almost nobody expects: the identical words ask God's enemies and God's people to cease doing different things.
He says, “Be still, and know that I am God; I will be exalted among the nations, I will be exalted in the earth.” Psalm 46:10 · New International Version
To the raging
To God's enemies the command is a demand to quit the field: Let his enemies be still, and
threaten no more, but know it, to their terror, that he is God, one infinitely above them, and
that will certainly be too hard for them
. Henry states the futility outright — let them
rage no more, for it is all in vain
.
To the trembling
To God's own people the same imperative asks for a different cessation: Let his own
people be still; let them be calm and sedate, and tremble no more, but know, to their comfort,
that the Lord is God
. What they are asked to stop is the managing — let him alone to
maintain his honour, to fulfil his own counsels and to support his own interest in the
world
. In Henry's period idiom, sedate is settled composure and let him alone
to means leave it to him: not passivity, but a change of hands.
The rendering, twice more
How translations carry the imperative differs at exactly the point Henry's reading turns on:
“ Stop striving and know that I am God; I will be exalted among the nations, I will be exalted on the earth.” Psalm 46:10 · New American Standard Bible
“Be still and know that I am God; I will be exalted among the nations, I will be exalted over the earth.” Psalm 46:10 · Berean Standard Bible
A note on the Hebrew, kept honest
Word studies of this verse usually report that the Hebrew imperative means to slacken or let drop. This site's audited source — Henry's exposition of the chapter — contains no philology at all, so no lexical claim about the Hebrew verb is made here. The cessation reading above is presented strictly as Henry's gloss of the English command. When a source this site can cite carries the Hebrew, this section will grow; not before.
Next: why the same sentence is addressed to both sides at once.