Of rams horns, or, of the jubilees, i.e. such trumpets wherewith they were to sound in the years of jubilee, Leviticus 25:9. Either this, or one of the other six, was certainly a sabbath day; and it is not material which was it, for the command of the Lord of the sabbath was sufficient to legitimate any action.
Related Commentaries of Joshua 6:4
Joshua 6:4
4 And seven priests shall bear before the ark seven trumpets of rams' horns: and the seventh day ye shall compass the city seven times, and the priests shall blow with the trumpets.