Upon this...
Upon this, three of the Arabs; Muadh ibn Jubail, Bishr ibn Bara and Dawud ibn Salamah, who had renounced idolatory and accepted Islam, reminded them in the following words: "O Jews; Fear Allah and accept Islam; because you yourself used to pray for victory over us by the right of Muhammad (s.a.w.), while we were idolators, remember you used to praise him and foretell his prophethood and describe his attributes to us" To this Salam ibn Mushkim; the Jew, replied that Muhammad (s.a.w) brought nothing to them they knew and he is not the prophet, which they were telling about.
To refute these Jewish denials the above verse was revealed. 4 Al-Aiyashi, in his famous exegesis on the holy Qur'an has recorded Imam Ja'afar As-Sadeq's (a.s.) narration to Abu Basir. The Imam says that the Jews had been informed in their books, that the migration (Hejira) route of the last Prophet would pass through somewhere between the places called 'Ayr' and 'Ohud'. in the Hejaz. 5 Keen to locate the place the Jews migrated to the Hejaz to await the eventual coming of the last Reformer.
Passing along Mount Hadad, they thought it rhymed perfectly with the predicted Ohud and they dispersed along the valley, making settlements in 'Taima', 'Fadak' and 'Khaiber'. After some time a group of Taima Jews longing to see their brethren, hired the services of a Bedouin and his camels, who promised to show them the predicted lands, called Ayr and Ohud. When the party reached the city of Yathreb (Medina) the Bedouin told them that this is Ayr and that is Ohud.
Immediately the Jews dismounted and informed the Bedouin that they no longer required either his services or his camels, because they had reached their avowed goal and intend to settle there. They wrote to their brethren in Fadak and Khaiber about their discovery of the promised place and invited them to join them in Yathreb.
The Khaiber and Fadak Jews, as they had grown roots in those places showed reluctance in deserting their settlements, but however assured the Yathreb Jews, that since it is in close proximity to their places, when it happens (the appearance of the awaited Prophet), they will rush to Yathreb. Gradually as time passed the Jews, profiting in trade and commerce amassed considerable wealth and bought large properties in and around Yathreb .
Their new found wealth and prosperity attracted the covetous eyes of 'Tubba', King of Yemen, who raided them.