Then look as to how was the end of those who were warned.
Note the consequences for those who have been warned.
See then the end of those who were warned
Except the servants of Allah, the purified ones
So look/see/wonder about how was the warned's/given notice's end/turn (result)
Now see how terrible is the destiny of those who rejected God’s warnings
Therefore see what sort of fate befell those who were warned
Behold, then, how evil was the end of those who were warned
So see how was the end of those who were warned
Behold! then, how (evil) was the end of those who were warned
Then see what was the end of those who were warned (but heeded not)