The Boil of Isaiah

Hezekiah had a boil on his skin, which would have prevented him from entering the courts of the Lord. He asked Isaiah what should be the sign that he could go up to the temple and enter into holy space. In verse seven, Isaiah says bring a cake of figs and let them take it and lay it on the boil so that he may recover. This is probably in reference to a sundial with steps where shadows lengthen as sun goes down. And then Isaiah called to the Lord and he brought the shadow back 10 steps by which it had gone down on the steps of a has.