Lamentations 3:44

Thou hast covered thyself with a cloud
With wrath and anger, as a cloud; he wrapped up himself in thick darkness, so as not to be seen or come at: sin, when it appears not pardoned, is as a cloud between God and his people; and this causes him to show his anger and displeasure; which is the cloud about him, Or the hiding of his face. The Targum is,

``thou hast covered the heavens with the clouds of thy glory:''

that [our] prayer should not pass through;
in such circumstances God seems to his people to be inexorable; and not a God hearing and answering prayer, as he is; as if there was no access unto him, or audience to be had of him, or acceptance of persons and prayers with him; whereas the throne of grace is always open and accessible: and there is a new and living way for believers always to approach unto God in; he is on a mercy seat, ready to receive and hear their prayers.