33 “‘When a foreigner resides among you in your land, do not mistreat them. 34 The foreigner residing among you must be treated as your native-born. Love them as yourself, for you were foreigners in Egypt.
to Deuteronomy 24:19
When you are harvesting in your field and you overlook a sheaf, do not go back to get it. Leave it for the foreigner, the fatherless and the widow, so that the Lord your God may bless you in all the work of your hands.
The Lord watches over the foreigner and sustains the fatherless and the widow, but he frustrates the ways of the wicked.
9 “This is what the Lord Almighty said: ‘Administer true justice; show mercy and compassion to one another. 10 Do not oppress the widow or the fatherless, the foreigner or the poor.
In Ezekiel, mistreating foreigners is one of the sins of that day's Jerusalem as the prophet lays out his charges.
How many tells them to take a hike? Not too many
In Nehemiah, the Israelites segregated themselves for purification when rededicating themselves after returning from exile.
Of course, foreign gods are warned against, as was marrying foreign women who would be worshiping those false foreign gods.
If we're to apply this to modern immigration issues, showing mercy on the foreigners among us seems to be a high priority. Segregating the faithful away from foreigners doesn't seem to be much of an issue, as that was something of a special case.
In the current case of the Central American refugees, the foreign gods issue is moot since they are going to be at least nominally Catholic by and large; it would take a strong spirit of Know-Nothingism to try and make that case with a straight face.
Putting refugee children on the first plane back to Tegucigalpa (I actually spelled that one right from memory!) might be the desired policy of some immigration hawks, but it would seem to be the wrong thing to do, at least in the short term.