Read teaching in   Parshah 15 [Exodus 10:1 – 13:16] (PDF) 

Exodus 10:1 – 13:16    BO -  בוא - GO

The pictographic meaning of the Hebrew word Bo, בוא, which is spelled with the letter Bet and the
letter Aleph, means, to secure the strength of the House.  Read more in (PDF)