premise: Henrietta , however , was at that time engaged in a lengthy correspondence with Joe 's older and more serious brother , Morris , who was just about her own age and whom she had got to know well during trips to Philadelphia with Papa , when he substituted for <mask> Jastrow at Rodeph Shalom Temple there during its <mask> 's absence in Europe .
hypothesis: the proper context for <mask> here should be spiritual leader of a Jewish congregation; qualified to expound and apply Jewish law