That the end of this sign might not be forgotten or overlooked, is the occasion of its appointment thus celebrated by the Psalmist in a tribute of praise:--"Who laid the foundations of the earth, that it should not be removed for ever. Thou coveredst it with the deep as with a garment: the waters stood above the mountains. At thy rebuke they fled; at the voice of thy thunder they hasted away. They go up by the mountains; they go down by the valleys unto the place which thou hast founded for them. Thou has set a bound that they may not pass over; that they turn not again to cover the earth."[671] By a reference to the promise given when this sign was appointed, and which it was designed in every season to bring again into view, is the sin of idolatry--a breach of covenant with God--thus condemned:--"Fear ye not me? saith the Lord: will ye not tremble at my presence, which have placed the sand for the bound of the sea, by a perpetual decree, that it cannot pass it; and though the waves thereof toss themselves, yet can they not prevail; though they roar, yet can they not pass over it. But this people hath a revolting and a rebellious heart; they are revolted and gone. Neither say they in their heart, Let us now fear the Lord our God, that giveth rain, both the former and the latter, in his season: he reserveth unto us the appointed weeks of the harvest." The practices of the people so addressed are also thus described,--"Though they say, The Lord liveth; surely they swear falsely." "Thy children have forsaken me, and sworn by them that are no gods." And their consequent privations are in like manner introduced. "Your iniquities have turned away these things, and your sins have withholden good things from you."[672] That this token was to designate the continuance of a covenant, the blessings of which were not merely temporal, but spiritual and eternal too, and whose duties--incumbent on those who surround the altar of God and swear by his name, should still be performed, we are taught by his own words,--"This is as the waters of Noah unto me: for as I have sworn that the waters of Noah should no more go over the earth; so have I sworn that I would not be wroth with thee, nor rebuke thee. For the mountains shall depart, and the hills be removed; but my kindness shall not depart from thee, neither shall the covenant of my peace be removed, saith the Lord that hath mercy on thee."[673]