Deuteronomy is all about the remembrance. It's the 5th book in the Pentateuch, and a rather lovely synopsis of the history of the Israelites and of God's instructions for their new nation. Moses summoned the people, and reminded them all about how the Lord had done for them. He reminded them of the rules for the clean and unclean meats. He reminded them of how God provided for them in the desert. He reminded them of how they were to make sacrifices. He reminded them over and over and over how important it was to care for the immigrants, orphans, and widows.
In every single community, there are immigrants and orphans and widows. Just as in the day that Moses authored the book of Deuteronomy, the immigrants and orphans and widows are still the most fragile, vulnerable people in our midst. The Bible is very clear: it is our responsibility to care for those who need it, in whatever way we can, which includes the immigrants and orphans and widows.