Jamieson, Fausset and Brown on Isaiah 43:4

4. Since--All along from the beginning; for there was never a time when Israel was not Jehovah's people. The apodosis should be at, "I will give." "Since ever thou wast precious in My sight, honorable, and that I loved thee, I will give," &c. [Maurer]. Gesenius, as English Version, takes "Since" to mean, "Inasmuch as." If the apodosis be as in English Version, "Since thou wast precious" will refer to the time when God called His people out of Egypt, manifesting then first the love which He had from everlasting towards them (Jr 31:3; Ho 11:1); "honorable" and "loved," refer to outward marks of honor and love from God.

men ... people--other nations for thee (so Is 43:3).

thy life--thy person.