Er his firstborn # 01_GEN_38_06 # And Judah took a wife for Er his firstborn, whose name [was] Tamar. 
Jether his firstborn # 07_JUD_08_20 # And he said unto Jether his firstborn, Up, [and] slay them. But the youth drew not his sword: for he feared, because he [was] yet a youth.