PITTSBURGH — After surviving the deadliest antisemitic attack in US history, after presiding over multiple funerals for his slain congregants, Rabbi Jeffrey Myers struggled to pray.“There was this emptiness to it,” recalls Myers, of Tree of Life Congregation in Pittsburgh.He turned to the biblical Book of Psalms — its hymns, poetry, and prayers covering “the entire spectrum of human existence and emotion, from elation to utter despair,” Myers recalled. “Something told me it’s in there somewhere, the inspiration that I need.”He started reading all 150 chapters, in order. When he got to 121, he found words that clicked: “My help...