3,400. The Biblical Obligation of Terumah

Hilchos Maaser 3:25

If someone consecrates produce that was detached from the ground and redeems it from the Temple treasury before the labors of this produce are completed, it must be tithed. If the labors were completed while the produce was sanctified and he later redeemed it, then it need not be tithed. If someone consecrates standing grain for flour offerings, it is exempt from tithes.

Hilchos Maaser 4:1

Under Biblical law, produce must only be tithed when one brings it into his house. This is derived from Deuteronomy 26:13: “I removed the holy produce from the house.” This is only the case when he brings the produce in through the gate, as per Deut. 26:12: “you shall eat within your gates.” If he brought the produce in via the roof or his yard, then the produce is exempt from terumah and maaser (under Biblical law).