The Cambridge Greek Professorship, which had before been denied him, was obtained by Barrow immediately after the Restoration. Soon afterwards he was chosen to be Professor of Geometry at Gresham College. In 1663 he preached the sermon in Westminster Abbey at the consecration of his uncle, Isaac, as Bishop of St. Asaph. In that year also he became, at Cambridge, the first Lucasian Professor of Mathematics, for which office he resigned his post at Gresham College. As Lucasian Professor of Mathematics, Isaac Barrow had among his pupils Isaac Newton. Newton succeeded to the chair in 1669. Barrow resigned because he feared that the duties of the mathematical chair drew his thoughts too much from the duties of the pulpit, towards the full performance of which he had desired all studies to be aids. He was then intent upon the writing of an "Exposition of the Creed, Decalogue, and Sacraments." He held a prebend in Salisbury Cathedral, and a living in Wales, that yielded little for his support after the Professorship had been resigned. But he was one of the King's chaplains, was made D.D. by the King in 1670, and in 1672 he was appointed Master of Trinity by Charles II., who said, when he appointed Isaac Barrow, "that he gave the post to the best scholar in England." Barrow was Vice-Chancellor of the University when he died in 1677, during a visit to London on the business of his college. The sermons here given were first published in 1678, in a volume entitled "Several Sermons against Evil-speaking." That volume contained ten sermons, of which the publisher said that "the two last, against pragmaticalness and meddling in the affairs of others, do not so properly belong to this subject." The sermons here given follow continuously, beginning with the second in the series. The text of the first sermon was "If any man offend not in word, he is a perfect man." The texts to the last three were: "Speak not evil one of another, brethren;" "Judge not;" and "That ye study to be quiet, and to do your own business."