Though he fall - That is, though he is sometimes disappointed; though he is not always successful; though he may be unfortunate - yet this will not be final ruin. The word here does not refer to his falling into “sin,” but into misfortune, disappointment, reverses, calamities. The image is that of a man who is walking along on a journey, but who stumbles, or fails to the earth - a representation of one who is not always successful, but who finds disappointment spring up in his path.
He shall not be utterly cast down - The word used here - טול ṭûl - means to “throw down at full length, to prostrate;” then, “to cast out, to throw away.” Compare Isaiah 22:17; Jeremiah 16:13; Jeremiah 22:26; Jonah 1:5, Jonah 1:15. Here it means that he would not be “utterly” and “finally” prostrated; he would not fall so that he could not rise again. The calamity would be temporary, and there would be ultimate prosperity.
For the Lord upholdeth him with his hand - It is by no power of his own that he is recovered, but it is because, even when he falls, he is held up by an invisible hand. God will not suffer him to sink to utter ruin.