It is narrated from Abu Jamilah, a man of Banu Sulaym, that in the time of Sayyiduna Umar (may Allah be pleased with him) he found a foundling child, and he took it to Sayyiduna Umar bin al-Khattab (may Allah be pleased with him). He said: "What made you pick up this soul?" He said: "I found it abandoned, so I took it." The overseer of my tribe said to him: "O Commander of the Believers! He is a righteous man." Sayyiduna Umar (may Allah be pleased with him) said: "Is that really so?" He said: "Yes." Sayyiduna Umar (may Allah be pleased with him) said: "Go, for he is free; his wala' (right of clientage) is yours, and his maintenance is on us." One narration has the words that he found a child and brought him to Sayyiduna Umar (may Allah be pleased with him), and Sayyiduna Umar (may Allah be pleased with him) said to him: "He is free, his wala' is yours, and his maintenance is on us, from the public treasury."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب اللقطة / 12133