What does Deuteronomy 26:13 mean?

Then you’ll say to the Lord, ‘I’ve taken out the sacred portion from my house and given it to the Levites, the foreigners, the orphans, and the widows, just like you told me. I haven’t broken your command or forgotten any of it.’ Deuteronomy 26:13 - Modern Text Bible

(This is a declaration of honesty and obedience, showing you’ve done what God asked with the tithe.)