'Stumbles' in the Bible

Do not rejoice and gloat when your enemy falls,And do not let your heart be glad [in self-righteousness] when he stumbles,

No one among them is weary or stumbles,No one slumbers or sleeps;Nor is the belt at their waist undone [as if unprepared for action],Nor is the strap of their sandal broken.

In that day the Lord will defend the people of Jerusalem, and the one who is impaired among them in that day [of persecution] will become [strong and noble] like David; and the house of David will be like God, like the Angel of the Lord [who is] before them.