Charles Ellicott Commentary Genesis 45:7

"And God sent me before you to preserve you a remnant in the earth, and to save you alive by a great deliverance." — Genesis 45:7 (ASV)

To preserve you a posterity in the earth.—Hebrew: To put for you a remnant in the land, that is, to preserve a remainder for you, as the word is translated in 2 Samuel 14:7. During the seven years’ famine, many races probably dwindled away, and the Hebrews, as mere sojourners in Canaan, would have been in danger of total extinction.

By a great deliverance.—That is, by a signal interference on your behalf. But the word translated “deliverance,” more precisely signifies that which escapes (see 2 Kings 19:31, where, as here, it is joined with the word remnant, and 2 Kings 19:30, where it is itself translated remnant). The two nouns truly signify the same thing; but whereas in the first clause the words seem to forebode that only a few would escape, in the second there is the assurance of their surviving in such numbers as to be able to grow into a great nation.