Tertullian

“ Similarly on other points also, you reproach Him with fickleness and instability for contradictions in His commandments, such as that He forbade work to be done on Sabbath-days, and yet at the siege of Jericho ordered the ark to be carried round the walls during eight days; in other words, of course, actually on a Sabbath. You do not, however, consider the law of the Sabbath: they are human works, not divine, which it prohibits. ”