the fatherless child: a young person whose father has died, left without his protection and provision
This word names a child who has lost a father. In the ancient world a father was a household's protector and provider, and the law courts and land rights ran through him, so a child without one had no standing and no shield. The fatherless child is not necessarily an orphan in the modern sense of having lost both parents: very often the mother is still alive, which is why this word keeps company with the widow. Together they picture a family stripped of the man who kept it safe.
Throughout the Hebrew Bible the fatherless child stands as the model of the defenseless person. The word appears again and again in a fixed group of three: the fatherless, the widow, and the foreigner living among the people. These are the ones with no one to take their side, and God repeatedly names them as the special objects of his own care. The law commands that they be left grain at harvest, given a share of the tithe, and never deprived of justice in court.
Because of this, the word carries weight far beyond a simple family description. To wrong the fatherless is presented as one of the surest marks of a corrupt society and a target of God's anger, while to defend them is held up as the heart of true justice and genuine devotion to God. The prophets measure a nation by how it treats them.