How is Sol Kurc described in the novel, We Were the Lucky Ones?

Sol, the patriarch of the Kurc family, owned a fabric shop in Radom before the war. He is described as a tough businessman, referred to around town as the "King Negotiator" but as Nechuma notes, "his children knew well that deep down he was as soft as a mound of freshly churned butter" (18), especially where they are concerned.