Vincent's NT Word Studies
18. He saith (lalei). Emphasizing the purport of the saying.A little while (to mikron). In vv. 16, 17, without the article. Here the article the or this little while defines the special point of their difficulty; this "little while" of which He speaks.
We cannot tell (ouk oidamen). Rev., more simply and literally, we know not.
He saith (lalei). Emphasizing the form of the saying.