'Look not back behind thee,' as in Genesis 19:17, means that Lot, who represents the good of charity, should not look to matters of doctrine. 'To look up,' is to look to celestial things. In Genesis 18:22, looking signifies thinking because seeing denotes understanding.

(Odkazy: Arcana Coelestia 2245)

7782. 'And there will be a great cry in the whole land of Egypt' means deep grief. This is clear from the meaning of 'a cry' - which goes up because the firstborn are dead, in the internal sense because of damnation - as grief. The reason why 'a great cry' means deep grief is that the greater the grief, the deeper it is.