"before the L-rd your G-d": This is the ma'aser (tithe) confession.
"I have removed the holy thing": This is second-tithe (viz. Vayikra 27:30) and neta revai (fruit of the fourth year [viz. Vayikra 19:24]).
"I have given it to the Levite": This is first-tithe. "And I have also given it": This is terumah and terumath ma'aser.
"to the stranger, to the orphan, and to the widow": This is second-tithe, leket, shikchah, and peah, even though their omission in the confession does not invalidate it.
(Bamidbar 15:20) Variantly: "from the house": Once it has been removed from the house, nothing further is required.