A soul hidden in God has an invisible defence which repels assaults. As with a man in a diving-bell, the sea may press on the crystal walls, but cannot crush them in or enter, and there is safe, dry lodging inside, while sea billows and monsters are without, close to the diver and yet far from him. Ver. 19 is full of difficulty, and most probably has suffered some textual corruption. To "hear and answer" is uniformly an expression for gracious hearing and beneficent answering. Here it can only mean the opposite, or must be used ironically. God will hear the enemies' threats, and will requite them. Various expedients have been suggested for removing the difficulty. It has been proposed to read "me" for "them," which would bring everything into order--only that, then, the last clauses of the verse, which begin with a relative ("who have no changes," etc.), would want an antecedent. It has been proposed to read "will humble them" for "will answer them," which is the LXX. translation. That requires a change in the vowels of the verb, and "answer" is more probable than "humble" after "hear." Cheyne follows Olshausen in supposing that "the cry of the afflicted" has dropped out after "hear." The construction of ver. 19 _b_ is anomalous, as the clause is introduced by a superfluous "and," which may be a copyist's error. The Selah attached is no less anomalous. It is especially difficult to explain, in view of the relative which begins the third clause, and which would otherwise be naturally brought into close connection with the "them," the objects of the verbs in _a_. These considerations lead Hupfeld to regard ver. 19 as properly ending with Selah, and the remaining clauses as out of place, and properly belonging to ver. 15 or 18; while Cheyne regards the alternative supposition that they are a fragment of another psalm as possible. There is probably some considerable corruption of the text, not now to be remedied; but the existing reading is at least capable of explanation and defence. The principal difficulty in the latter part of ver. 19 is the meaning of the word rendered "changes." The persons spoken of are those whom God will hear and answer in His judicial character, in which He has been throned from of old. Their not having "changes" is closely connected with their not fearing God. The word is elsewhere used for changes of raiment, or for the relief of military guards. Calvin and others take the changes intended to be vicissitudes of fortune, and hence draw the true thought that unbroken prosperity tends to forgetfulness of God. Others take the changes to be those of mind or conduct from evil to good, while others fall back upon the metaphor of relieving guard, which they connect with the picture in ver. 10 of the patrols on the walls, so getting the meaning "they have no cessation in their wicked watchfulness." It must be acknowledged that none of these meanings is quite satisfactory; but probably