KNOW (3)

Know, v. i. 1. 1. To have knowledge; to have a clear and certain perception; to possess wisdom, instruction, or information; — often with of.
Israel doth not know, my people doth not consider. Is. i. 3. If any man will do his will, he shall know of the doctrine, whether it be of God, or whether I speak of myself. John vii. 17. The peasant folklore of Europe still knows of willows that bleed and weep and speak when hewn. Tylor. 2. 2. To be assured; to feel confident.
To know of, to ask, to inquire. “ Know of your youth, examine well your blood.” Shak.