WHEN WHAT IS to happen comes to pass --
When the forthcoming event does occur.
When the Terror descends
WHEN THAT which must come to pass [at last] comes to pass,
When there happeneth Event.
When the Event (i.e. the Day of Resurrection) befalls.
When the inevitable occurs.
When the Event will come to pass
When the Waqi`ah occurs
When the event befalleth -
When the Imminent [Hour] befalls
When the Event (the resurrection) comes
When the Occurrence occurs,
When the inevitable event comes,
When the great event comes to pass,
I<u>tha</u> waqaAAati alw<u>a</u>qiAAat<b>u</b>
When the inevitable event takes place,
When the Event inevitable cometh to pass,