يَتِيمًا
To an orphan,
meaning, he gives food on a day like this to an orphan.
ذَا مَقْرَبَةٍ
near of kin.
meaning, who is related to him.
Ibn Abbas, Ikrimah, Al-Hasan, Ad-Dahhak and As-Suddi all said this.
This is similar to what was related in a Hadith that was collected by Imam Ahmad on the authority of Salman bin Amir who said that he heard the Messenger of Allah say,
الصَّدَقَةُ عَلَى الْمِسْكِينِ صَدَقَةٌ وَعَلَى ذِي الرَّحِمِ اثْنَتَانِ
صَدَقَةٌ وَصِلَة
Charity given to the poor person is counted as one charity, while if it is given to a relative it is counted as two;
- charity and
- connecting the ties (of kinship).
At-Tirmidhi and An-Nasa'i both recorded this Hadith and its chain of narration is authentic.
Then Allah says,
أَوْ مِسْكِينًا ذَا مَتْرَبَةٍ