119 - Al-Hasan ibn al-Haytham informed me that Muhammad ibn Musa ibn Mashish narrated to them that he asked Abu 'Abd Allah [Ahmad ibn Hanbal]: "If someone seeks aid against the enemy, such as [those like] Babak and his ilk, from the people of this city, is it incumbent upon the people of this city to go forth [to assist]?" He replied: "It is incumbent upon those who are in closest proximity, then the next nearest. It was said: "And if they do not provide aid?" He said: "Then they have neglected what is upon them [their duty]."