ἐξαίφνης

And as he journeyed, he came near Damascus: and suddenly there shined round about him a light from heaven:

And it came to pass, that, as I made my journey, and was come nigh unto Damascus about noon, suddenly there shone from heaven a great light round about me.

And suddenly there was with the angel a multitude of the heavenly host praising God, and saying,

And, lo, a spirit taketh him, and he suddenly crieth out; and it teareth him that he foameth again, and bruising him hardly departeth from him.

Lest coming suddenly he find you sleeping.