John Gill Commentary Psalms 37:24

"Though he fall, he shall not be utterly cast down; For Jehovah upholdeth him with his hand." — Psalms 37:24 (ASV)

Though he fall
Into temptation, and by it into sins, and these very great ones; from a lively and comfortable exercise of grace, and a degree of steadfastness in the doctrine of grace:

he shall not be utterly cast down ;
because he is in the arms of everlasting love, and in the hands of Christ Jesus; is on him as the sure foundation, and is kept by the power of God through faith unto salvation, and so shall not perish, but have everlasting life;

for the Lord upholdeth [him with] his hand ;
with the right hand of his righteousness, and keeps him from falling finally and totally; see (Isaiah 41:10) ; and (See Gill on Psalms 37:17).