“He sitteth alone and keepeth silence, because He hath borne it upon him. He putteth his mouth in the dust; if so be there may be hope.”-Lamentations 3:28, 29.

The prophet describes the conduct of a person in deep anguish of heart. When he does not know what to do, his soul, as if by instinct, humbles itself. He gets into some secret place, he utters no speech, he gives himself over to moaning and to tears, and then he bows himself lower and yet lower before the Divine Majesty, as if he felt that the only hope for him in the extremity of his sorrow was to make complete submission to God, and to lie in the very dust before Him.

It seems to me that such conduct as this, which is characteristic of every truly gracious man in his hour of trouble, should also be the mark of all who are seeking God’s grace, those who are not yet saved, but who are conscious of their need of salvation. I must, surely, be speaking right into the heart of some who are feeling the crushing weight and heavy burden of their guilt. If you cannot do anything else, dear friends, do what these two verses say, in order that, afterwards, you may be able to take that grand gospel step of faith in Jesus Christ which will certainly bring you into peace and joy.

Those of you who have the Revised Version will notice a correction which has been made long ago by all competent scholars:-“Let him sit alone and keep silence, because He hath laid it upon him. Let him put his mouth in the dust; if so be there may be hope.” It does not matter which way you read the passage, because the conduct of one gracious man is virtually a precept to another; yet it is satisfactory to find that, if we are under the burden of sin, we are here commanded to do as the prophet did in his time of need. ~ C.H.Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2468.cfm