Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: "The people of greatest discernment are three: the daughter of the father-in-law of Sayyiduna Musa (peace be upon him), who said: 'O my father, hire him; indeed, the best one you can hire is the strong and trustworthy' [Surah al-Qasas: 26]. Her father asked: 'What did you observe of his strength?' She said: 'He came to the well, on which there was a rock that so many (men together) could not lift, and he lifted it.' Her father asked: 'What did you observe of his trustworthiness?' She said: 'I was walking in front of him, and he put me behind him.' The second is the Egyptian master of Sayyiduna Yusuf (peace be upon him), who said: 'Make his residence honourable; perhaps he will benefit us, or we may adopt him as a son' [Surah Yusuf: 21]. And the third is Sayyiduna Abu Bakr (may Allah be pleased with him), when he appointed Umar (may Allah be pleased with him) as his successor."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 8797