"21Thou shalt neither vex a stranger, nor oppress him: for ye were strangers in the land of Egypt. 22Ye shall not afflict any widow, or fatherless child. 23If thou afflict them in any wise, and they cry at all unto me, I will surely hear their cry; 24And my wrath shall wax hot, and I will kill you with the sword; and your wives shall be widows, and your children fatherless." (Exodus 22: 21-24)
In the Old Testament, the Lord had a special heart for three marginal groups: orphans, strangers, and widows.
Orphans are a weakened group because they have no parents, no protectors. They have no clear identity or pedigree, since they have no family, and they have no training to fall back on when they grow older.
Strangers are susceptible to fraud and deceit because they live in a country to which they do not belong. They do not speak the official language of the country where they live. They do not understand the customs. Everything that they say and do gives away that they are out of place.
Widows have lost their husbands, their source of sustenance, and also their source of power and authority in the ancient world. Without her man, a widow was as good as dead, and dependent on the help of others, easily deceived or taken advantage of.
So, orphans, strangers, and widows are special people to God. He cares about them to such a degree that He set in place a curse under the Old Covenant against anyone who would ill-treat anyone of these people.
What did God have in mind focusing on these individuals in the Old Testament?
He had everyone of us in mind, and more importantly He was placing types and shadows which would magnify His grace through His Son Jesus!