經律異相 1.102

1.102

電有四種。東方名身光。二南方名難毀。西方名流炎。北方名定明。何以虛空雲中有此電光。四方之電又共相觸。有此光起（出長阿含經第二十卷）。

There are four kinds of lightning: in the east, it is named Body Light; second, in the south, Hard to Destroy; in the west, Flowing Flame; in the north, Settled Brilliance. Why is there this lightning flash in the clouds of the sky? The lightning of the four directions also clashes together, causing this light to arise. (From the Dīrgha-āgama, fascicle 20.)