Joshua 6:15

‘ And so it was on the seventh day, that they rose early at the dawning of the day, and went round the city in the same way seven times, only on that day they went round the city seven times.'

This was not necessarily the Sabbath, but certainly one of the seven days must have been the Sabbath. Thus the Sabbath law was abrogated for this event. The sevenfold circling, the divinely perfect circling, was to demonstrate that the divine power of YHWH was now about to be revealed. This sevenfoldness would have had deep significance both for the Israelites and for the people shut up within the city. Once the men of the city realised that they were marching round seven times on the seventh day of marching the hearts of the men in the city would have grown cold within them. They would have realised that this fearsome God was about to act. And the men of Israel would have been aware of the same.