[Tantumergo]

"It is finished" refers to the completion of his Paschal sacrifice after he had drunk the "fourth cup" of the Haggadah i.e. the sour wine that they gave him to drink on the cross.

His work of redemption could not have been completed at this point as he hadn't yet risen.

What Polycarp may be referring to is St. Paul's teaching on purgatory in 1 Cor 3:13-15:

13 Every man's work shall be manifest; for the day of the Lord shall declare it, because it shall be revealed in fire; and the fire shall try every man's work, of what sort it is.
14 If any man's work abide, which he hath built thereupon, he shall receive a reward.
15 If any man's work burn, he shall suffer loss; but he himself shall be saved, yet so as by fire.

[drstevej]

***St. Paul's teaching on purgatory in 1 Cor 3:13-15***

Wasn't aware Paul ever uses the term purgatory. Reference?