Invasion of Bani Qainuqa'
We have already spoken about the treaty that the Prophet [PBUH] signed with the Jews. He was very careful to abide by it to the letter and the Muslims did not show the least violation of any of its provisions. The Jews, however, whose natural disposition is closely linked to treachery, betrayal and covenant-breaching, could not rid themselves of the tradition of theirs, and started a process of intrigues and troublemaking with the aim of producing schism in the growing solid Muslim ranks. Here is a relevant model of their behaviour: Shas bin Qais, an elderly Jew, a terrible disbeliever and a greatly envious man of the Muslims, passed by a group of Muhammad [pbuh]ís followers of Aws and Khazraj. He perceived a prevalent spirit of reconciliation and an atmosphere of rapport and amity enveloping the whole group; an unusual scene categorically in conflict with the animosity and hatred that characterized their pre-Islam behaviour. He, therefore, sent a youth of his to sit among them, remind them of BuĎath war between them and recite some of their verses which they used to compose satirizing each other; all of this with the intention of sowing the seeds of discord and disagreement and undermining the new Islamically-orientated inter-tribal relations. The youth did in fact succeed and the two parties at no time recalled the old days and pre-Islam tribal fanaticism sprang to the front to bring about a state of war.
The Prophet [PBUH] was reported of this account, and immediately, at the head of some Emigrants, set out to see to the situation. He began to rebuke them but in the manner of the great instructor and the tolerant spirit of the understanding guide: "O, Muslims! Do you still advance pre-Islamic arguments after I have been sent to you (as a Messenger). Remember that it is not rightful for you to turn backward after All‚h has guided you to the Straight Path, delivered you from disbelief and created amity between you." The Muslims readily realized that it was a Satanic whim and a plot hatched by the enemies. They directly embraced each other and went back home quite satisfied and in full obedience to the Messenger of All‚h [PBUH]. [Ibn Hisham 1/555, 556]
Such were the practices of the Jews, trouble-making, dissension-sowing, falsehood-fabrication, faking belief in the day, and practising disbelief at night. In everyday life, they used to tighten the ropes of financial dealings on the Muslims. If they happened to owe a Muslim something, they would shirk their obligations on grounds that he had converted into a new religion and they would allege the basis of agreement was no longer valid. If it was the other way, they would never cease to harass him day and night to pay back the debt, all of which in a desperate attempt to demolish the great edifice of the new religion that was rapidly gaining ground and speedily towering up skyward.