It is usually possible for something good to come out of bad situation. A silver lining on a cloud is an ideation that the sun is behind it. The potential for something positive or beneficial to result from a negative situation. One can derive some benefit from every bad thing that transpires to one. An element of hope or a redeeming quality in an otherwise bad situation, as in "The rally had a disappointing turmoil but the silver lining was that those who came pledged a great deal of money. This metaphorical term is a shortening of" Every cloud has a silver lining." In turn derived from John Milton's"Comus"," A sable loud turns forth its silver lining on the night." There is always something hopeful about even the most difficult or unhappy situation. The worst situation has some element of hope or dome redeeming quality. John Milton appears to have been the originator of this metaphor as mentioned above. It was adopted by numerous later writers and so was already a cliche by the time it appeared in the popular magazines.