ישעיהו ה:כז פירוש: רש״י ואבן עזרא

None is weary or stumbles among them No one will be weary and no one will stumble in his running, to fulfill (supra v. 19), “Let Him hurry, let Him hasten,” that they say before Him.

ינום He will slumber; נום signifies a sleep of a less profound kind than ישן. He will not slumber, much less will he sleep.

open up Heb. נִפְתַּח, an expression of untying, as (Genesis 24:32): “And he untied (וַיְפַתַּח) the camels.”