Ran across this rather amazing quotation in Thomas Goodwin’s works, volume 9, pg. 501. All preachers, beware!
Dost thou keep in upon the Sabbath day, and write and note the sermon, and repeat it, but thinkest thy Master’s house or thy study a prison all the while, and wouldst gladly be taking other liberties, but that thy tutor or master commands thee otherwise; and all that while thou lookest at them as thy jailors? If so, thou art then unthankful, though thou renderest and dost never so much for God.