The Pharisees and Sadducees, as is well known, were at opposite poles of thought; the one being the traditionalists, the other the sceptics, of the time, so that it was quite remarkable that they should unite in anything. They did, however, unite in this demand for a sign from heaven. Neither of them could deny that signs had been given,--that the blind had received sight, lepers had been cleansed, the lame healed, and deeds of mercy done on every side. But neither party was satisfied with this. Each was wedded to a system of thought according to which signs on earth were of no evidential value. A sign from heaven was what they needed to convince them. The demand was practically the same as that which the Pharisees and scribes had made before (xii. 38), though it is put more specifically here as a sign _from heaven_. The reason why the Pharisees adopted the same method of attack as before is not far to seek. Their object was not to obtain satisfaction as to His claims, but to find the easiest way of discrediting them; and, knowing as they did from their past experience that the demand of a special sign would be refused, they counted on the refusal beforehand, to be used by their new allies as well as themselves as a weapon against Him. They were not disappointed, for our Lord was no respecter of persons; therefore He spoke just as plainly and sternly when the haughty Sadducees were present as He had done before they made their appearance. The words are stern and strong; but here again it is "more in sorrow than in anger" that He speaks. We learn from St. Mark that, as He gave His answers, "He sighed deeply in His spirit." There had been so many signs, and they were so plain and clear--signs which spoke for themselves, signs which so plainly spelt out the words, "The kingdom of heaven is among you"--that it was unspeakably sad to think that they should be blind to them all, and find it in their heart to ask for something else, which in its nature would be no sign at all, but only a portent, a barren miracle.