Ishaq ibn Musa al-Ansari narrated to me, saying: Ma'n narrated to us, saying: Malik narrated to us. (Another chain:) Muhammad ibn al-Muthanna narrated to us, saying: Muhammad ibn Ja'far narrated to us, saying: Shu'bah narrated to us — all of them from al-'Ala' ibn 'Abd al-Rahman, with this chain of transmission. In Shu'bah's narration, there is no mention of ribat (guarding the frontier), while in Malik's narration, it is mentioned twice: "That is the ribat, that is the ribat."