Psa. 136:9 KJV (With Strong’s)

The moon
yareach (Hebrew #3394)
the moon
KJV usage: moon. Yrechow. See 3405.
Pronounce: yaw-ray'-akh
Origin: from the same as 3391
and stars
kowkab (Hebrew #3556)
a star (as round or as shining); figuratively, a prince
KJV usage: star((-gazer)).
Pronounce: ko-kawb'
Origin: probably from the same as 3522 (in the sense of rolling) or 3554 (in the sense of blazing)
to rule
memshalah (Hebrew #4475)
rule; also (concretely in plural) a realm or a ruler
KJV usage: dominion, government, power, to rule.
Pronounce: mem-shaw-law'
Origin: feminine of 4474
by night
layil (Hebrew #3915)
also laylah {lah'- yel-aw}; from the same as 3883; properly, a twist (away of the light), i.e. night; figuratively, adversity
KJV usage: ((mid-))night (season).
Pronounce: lah'-yil
Origin: or (Isa. 21:11) leyl {lale}
: for his mercy
checed (Hebrew #2617)
kindness; by implication (towards God) piety: rarely (by opposition) reproof, or (subject.) beauty
KJV usage: favour, good deed(-liness, -ness), kindly, (loving-)kindness, merciful (kindness), mercy, pity, reproach, wicked thing.
Pronounce: kheh'-sed
Origin: from 2616
endureth for ever
`owlam (Hebrew #5769)
from 5956; properly, concealed, i.e. the vanishing point; generally, time out of mind (past or future), i.e. (practically) eternity; frequentatively, adverbial (especially with prepositional prefix) always
KJV usage: alway(-s), ancient (time), any more, continuance, eternal, (for, (n-))ever(-lasting, -more, of old), lasting, long (time), (of) old (time), perpetual, at any time, (beginning of the) world (+ without end). Compare 5331, 5703.
Pronounce: o-lawm'
Origin: or lolam {o-lawm'}

Cross References

The moon and stars.The sun is the monarch of day, the state of light; the moon of the night, the state of darkness.
The rays of the sun falling on the atmosphere, are refracted and diffused over the whole of the hemisphere of the earth immediately under his orb; while those rays of that vast luminary which, because of the earth's smallness in comparison with the sun, are diffused on all sides beyond the earth, falling on the opaque disc of the moon, are reflected back on the lower hemisphere, or the part of the earth opposite the sun.
But the reflected light being 50,000 times less in intensity than that of the sun, there is a sufficient distinction between day and night, though each is ruled and determined by one of these two great lights.

J. N. Darby Translation

The moon and stars for rule overd the night, for his loving-kindness endureth for ever:

JND Translation Notes

Or "during."