Exodus 12:25-26

CKJV_Strongs(i)
  25 H935 And it shall come to pass, when you be come H776 to the land H3068 which the Lord H5414 will give H1696 you, according as he has promised, H8104 that you shall keep H5656 this service.
  26 H1121 And it shall come to pass, when your sons H559 shall say H5656 unto you, What mean you by this service?