The Jews of Spain did not remain neutral, and either willingly or perforce joined the one or the other party, as their interests or political opinions dictated. When Mahometans or Christians conspired, they could, in case of discovery, take refuge with their powerful co-religionists. The Jews, however, did not enjoy such protection, and could only hold together for safety. Treachery in their midst was, therefore, most disastrous for them, as the anger of the enraged rulers not only struck the conspirators or their congregation, but the entire Jewish population of the country. When, therefore, a member of the congregation of Lucena on one occasion threatened to betray his co-religionists, the rabbi and judge, Joseph Ibn-Migash, determined to make an example of him. He condemned the traitor to be stoned to death at twilight on the Day of Atonement. Joseph Ibn-Migash left a learned son, Meïr (1144), and a large circle of disciples, amongst whom was Maimun of Cordova, whose son was destined to begin a new era in Jewish history. In the measure in which the study of the Talmud in Spain grew, Bible exegesis and the study of Hebrew grammar declined. These branches were arrested in their development. But on the other hand, this period was rich in poets. The Hebrew language, during the two centuries since Ben-Labrat, had become smooth and pliable, so that it was no difficult matter to make verses, and employ rhyme and meter. The involved forms developed especially by Solomon Ibn-Gebirol found many imitators. The Arabic custom of writing letters of friendship in verses, adopted by the Spanish Jews, made a knowledge of prosody a necessity: he who did not desire to appear illiterate had to learn how to versify. The number of poems which at this period saw the light of day was legion. Amongst poets worthy of record, who also occupied themselves with matters other than poetry, were Judah Ibn-Giat, Judah Ibn-Abbas, Solomon Ibn-Sakbel, and the brothers Ibn-Ezra. They were all surpassed by the prince of poets, Jehuda Halevi, recognized even by his contemporaries as a master of song.