(Exodus 15:1) "Az yashir Mosheh": Az ("then") sometimes signals the past and sometimes signals the future. The past: (Genesis 4:26) "Az men began", (Exodus 4:26) "Az she said", (Exodus 15:1) "Az Moses sang", (Numbers 21:17) "Az Israel sang", (Joshua 10:12) "Az Joshua spoke", (I Chronicles 15:2) "Az David said", (I Kings 8:12) "Az Solomon said." And sometimes "Az" signals the future, viz.: Isaiah 60:5) "Az you will see and flow", (Ibid. 58:8) "Az your light shall break forth as the morning", "Then there shall be opened", (Ibid. 35:6) "Az the lame man shall leap as a hart", (Ibid. 5) (Jeremiah 31:12) "Az the virgin will rejoice in the dance", (Psalms 126:2) "Az our mouth will be filled with laughter", (Ibid.) "Az they will say among the nations."