* passover.
  2:13  5:1  6:4  Ex 12:11-14 
 * before.
  7:8-10  12:1  Ezr 3:1-6  Ne 8:1-12 
 * to purify.
  2:6  Ge 35:2  Ex 19:10,14,15  Nu 9:6  1Sa 16:5  2Ch 30:17-20 
  Job 1:5  Ps 26:6  Ac 24:18  1Co 11:28  Heb 9:13,14  Jas 4:8