Now are we sure that thou knowest ... - Their difficulty had been to understand what was the meaning of his declaration in John 16:16. About this they conversed among themselves, John 16:17-19. It is evident that they had not mentioned their difficulty to him, and that he had not even heard their conversation among themselves, John 16:19. When, therefore, by his answers to them John 16:20-28, he showed that he clearly understood their doubts; and when he gave them an answer so satisfactory without their having inquired of him, it satisfied them that he knew the heart, and that he assuredly came from God. They were convinced that there was” no need that any man should ask him,” or propose his difficulties to him, since he knew them all and could answer them.
Related Commentaries of John 16:30
John 16:30
30 Now are we sure that thou knowest all things, and needest not that any man should ask thee: by this we believe that thou camest forth from God.