 As Alex Metcalfe writes, "by undertaking a "jihad" to expand the frontiers of Islam at the expense of the infidels by conquest – the first major undertaking since the invasion of the Iberian Peninsula from 711 – they could silence the criticism of the jurists.At the same time, they could redirect the destructive energies of a restless "jund" across the Ifriqiyan–Sicilian channel to secure new sources of manpower and wealth".Ziyadat Allah's council was divided over the issue, but in the end the exhortations of the respected "qadi" of Kairouan, Asad ibn al-Furat, who used quotations from the "Quran" to support his case, swayed them.