John 16:30

Now are we sure that thou knowest all things - Is not the following the meaning of the disciples? We believe that thou art not only the Messiah who camest out from God, but that thou art that God who searchest the heart and triest the reins, and needest not to be asked in order to make thee acquainted with the necessities of thy creatures; for thou perfectly knowest their wants, and art infinitely disposed to relieve them.

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.

16:30 Thou knowest all things - Even our hearts. Although no question is asked thee, yet thou answerest the thoughts of every one. By this we believe that thou camest forth from God - They, as it were, echo back the words which he had spoken in 16:27 , implying, We believe in God; we believe also in thee.