This in its turn raised the inquiry whose interpretation of Scripture was to be accepted? which he answered by laying down the duty of private judgment and of the comparing of one part of Scripture with another. At length she very humbly remarked that she was not able to contend with him, but that if she had those present with her whom she had heard they could answer him, and he expressed his readiness to meet before her in argument "the learnedest papist in Europe." To this she somewhat tartly retorted, "You may perchance get that sooner {162} than you believe," and he replied a little sarcastically to the effect that if he ever got it, then indeed it would be sooner than he believed. He took his leave in this courtly yet scriptural fashion, "Madame, I pray God that you may be as blessed within the commonwealth of Scotland as ever Deborah was in the commonwealth of Israel." Thus for the first time they measured their strength, and the result was, in common speech, a draw. Mary found that Knox was made of more unyielding stuff than those whom heretofore she had been in the habit of meeting; and John formed an estimate of Mary's ability which his subsequent experience only served to confirm. It was to be no child's play between them. He could not afford to give so subtle and ready an adversary the least advantage. Writing to Cecil after this interview he says, "The Queen neither is, neither shall be of our opinion, and in very deed her whole proceedings do declare that the cardinal's lessons are so deeply printed in her heart that the substance and the quality are like to perish together. I would be glad to be deceived, but I fear I shall not. In communication with her I espied such craft as I have not found in such age." Matters went on after this with tolerable quietness for months, and Knox kept up his stated labours as the minister of Edinburgh. What these were seem now to be surprising. He preached twice every Sunday, and thrice besides during the week on other days. He met regularly once a week with his elders for the oversight of {163} the flock; and attended weekly the assembly of the ministers, for what was called "the exercise on the Scriptures." These stated and constant labours, with the addition of frequent journeyings by appointment of the General Assembly to perform in distant parts of the country very much the duty of a superintendent for the time, were exceedingly exhausting; and the city council, wishing to relieve him of some of his duties, came (in April, 1562) to a resolution to call the minister of the Canongate to undertake the half of his charge; but their object was not accomplished till June of the following year, when John Craig became his colleague.