Since thou wast precious in my sight, thou hast been honourable, and I have loved thee: therefore will I give men for thee, and people for thy life.
Since - Hebrew, meeasher (ex quo tempore), from the time that: all along from the beginning; because there was never a time when Israel was not Yahweh's people.
Since thou wast precious in my sight, thou hast been honourable ... therefore will I give men for thee.
The apodosis should be at "I will give." 'Since ever thou wast precious in my sight, honourable, and that I loved thee, I will give men for thee' (cf. Isaiah 43:3) (Maurer). Gesenius takes Since to mean, Inasmuch as (eo quod - i:e., quonium), a rare sense of the Hebrew. If the apodosis be as in the English version, and if the "since" refer to time, "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 in reality from everlasting toward them (Jeremiah 31:3; Hosea 11:1). "Honourable" and "loved" refer to the outward marks of honour and love from God, whereby at the Exodus He marked Israel as His special people.
Therefore will I give men for thee, and people - other nations for thee (so Isaiah 43:3).
For thy life - thy person.