John Gill Commentary John 16:29

"His disciples say, Lo, now speakest thou plainly, and speakest no dark saying." — John 16:29 (ASV)

His disciples said to him Upon the above discourse of Christ, such rays and beams of light darted into the minds of the apostles, and things stood so clear in their view, and they so well understood what Christ had said, that they declare,

lo, now you speak plainly, and speak no proverb: what he had said before, were to them like proverbial, or parabolical expressions, not easy to understand; they were like enigmas, riddles, and dark sayings, whose meaning they could not understand; but now they observe, with admiration, that what he delivered was plain, and intelligible;

This was due not so much to a change in Christ's way of speaking as to their former dullness of hearing and their now having received further light.