Wikipedia
Ansarullah (; Helpers [in the cause] of Allah) is an auxiliary organization of the Ahmadiyya Muslim Community for men of age 40 and over. The name "Ansarullah" is an Arabic expression meaning "helpers of Allah." It is taken from a verse of the Holy Qur'an, “And when Jesus perceived their disbelief, he said, ‘Who will be my helpers in the cause of Allah?’ The disciples answered, ‘We are the helpers of Allah. We have believed in Allah. And bear thou witness that we are obedient” (Āle`Imrān [Chapter 3]: Verse 53). Historically, the name refers to the residents of Medina who welcomed and granted asylum to Muhammad and the migrating Muslims after Hijrah (see Ansar (Islam)).
All Ahmadi Muslims who are forty years of age or over comprise the general body of 'Ansarullah.' Majlis Ansarullah, like the main body of the Ahmadiyya Muslim Community – to which it is subordinate – is a non-political, religious and spiritual organization.