Tractate Challah - Chapter 3 - Mishnah 4 חלה פרק ג׳ משנה ד׳

Similarly one who dedicates his produce prior to the stage when they are subject to tithes and then redeemed them, they are liable [to be tithed]. If [he dedicated them] when they had already become subject to tithes and then redeemed them, they are liable [to be tithed]. If he dedicated them before they had ripened, and they became ripe while in the possession of the [Temple] treasurer, and he then redeemed them, they are exempt, since at the time when they would have been liable, they were exempt.