Isaiah 40:28

Hast thou not known? hast thou not heard that the everlasting God the LORD the Creator of the ends of Hast thou not known? hast thou not heard, that the everlasting God, the LORD, the Creator of the ends of the earth, fainteth not, neither is weary? there is no searching of his understanding.

Hast thou not known - by thine own observation and reading of Scripture.

Hast thou not heard - from tradition of the fathers.

(That) the everlasting ... ? These attributes of Yahweh ought to inspire His afflicted people with confidence.

(There is) no searching of his understanding - therefore thy cause cannot, as thou sayest, escape His notice: though much in His ways is unsearchable, He cannot err (Job 11:7). He is never "faint" or "weary" with having the countless wants of His people ever before Him to attend to.