whereupon a visitation for thy Sustainer came upon that [garden] while they were asleep,

Then there came on the (garden) a visitation from thy Lord, (which swept away) all around, while they were asleep.

Then a visitation from thy Lord came upon it while they slept

But a visitation from thy Lord came on it, while they slept.

So there came upon the garden an affliction from your Lord while they were asleep.