Sayyiduna Abdullah bin Ja'far (may Allah be pleased with them both) narrated: I would ask Sayyiduna Ali (may Allah be pleased with him) for something and he would refuse me, so I would say: By the right of Ja'far. And whenever I said, "By the right of Ja'far," he would give it to me.
Hadith Referenceالمعجم الكبير للطبراني / باب الجيم / 1463