The second line of the fifth verse, modifying "our true Paschal Lamb" from the previous line, is "Whom God so freely gave us," sung to this musical phrase:
"Freely" is sung with a melisma (A G F), musically giving a sense of degree (for "so").
There are three instances in the hymn where "forever" is sung with a melisma, giving a sense of duration. The first is about halfway through the third verse, in the line "From death's pale brow forever," sung to the same phrase as above. "Forever" is sung to the notes G F E D.
The other two instances are in the line "Its sting is lost forever," which occurs near the end of the third and fourth verses. "Forever" is again sung to the notes G F E D, but the musical phrase is a bit different from that above:
