Zayd b. Sa'ne, the Jewish scholar who became a Muslim

Zayd b. Sa'ne was a distinguished Jewish rabbi known for his wealth and scholarship in Medina. Well-versed in the Torah, Zayd had read about the attributes of the final prophet foretold to come and was researching with great curiosity. When he saw the Prophet Muhammad, he identified the majority of the signs of prophethood in him; however, he had not yet verified two attributes: whether his forbearance increased in the face of slight rudeness, and whether his patience strengthened as provocation increased. To test these two attributes, he devised a plan: he lent the Prophet eighty dinars to be repaid by a predetermined date. A few days before the deadline, Zayd seized the Prophet by the collar and harshly said, "O sons of Abd al-Muttalib! You always pay your debts late!" Disturbed by this behavior, Umar attempted to reprimand Zayd. But the Prophet was watching the incident with a smile. The Messenger turned to Umar and said, "O Umar! Neither I nor this man expected this from you. You should have advised me to repay my debt kindly and him to ask for his due kindly." Then the Prophet commanded Umar to pay Zayd his debt and to add twenty sa' of dates on top (since he had frightened him). When Umar paid the debt, Zayd said he had now seen the attributes he was looking for: as rudeness increased, the Prophet's forbearance had also increased. Thereupon, he declared the shahada and accepted Islam. Zayd b. Sa'ne passed away during the Battle of Tabuk or on the way back. He was present at the funeral of the Prophet. [Source: Mehmet Efendioğlu, "Zayd b. Sa'ne" article, TDV Islamic Encyclopedia, islamansiklopedisi.org.tr/zeyd-b-sane; Hâkim, el-Müstedrek, III, 700; Beyhakî, Delâilü'n-nübüvve, VI, 259]