Mark me, and be astonished - Consider and compare the state in which I was once, with that in which I am now; and be astonished at the judgments and dispensations of God. You will then be confounded; you will put your hands upon your mouths, and keep silent. Putting the hand on the mouth, or the finger on the lips, was the token of silence. The Egyptian god Harpocrates, who was the god of silence, is represented with his finger compressing his upper lip.
Mark me - Margin, “look unto.” Literally, “Look upon me. That is, attentively look on me, on my sufferings, on my disease, and my losses. See if I am a proper object of repreach and mockery - see if I have not abundant reason to be in deep distress when God has afflicted me in a manner so unusual and mysterious.
And be astonished - Silent astonishment should be evinced instead of censure. You should wonder that a man whose life has been a life of piety, should exhibit the spectacle which you now behold, while so many proud contemners of God are permitted to live in affluence and ease.
And lay your hand upon your mouth - As a token of silence and wonder. So Plutarch, de Iside et Osiride, “Wherefore, he had laid his finger on his mouth as a symbol of silence and admiration - ἐχεμυθίας καὶ σιωπῆς σύμβολον echemuthias kai siōpēs sumbolon f0.”