Hadith of Abu al-Hassan Musa, 'Alayhim al-Salam to Ali ibn Suwayd — Hadith 1

So the weak is the one who cannot argue against (the batil) and he does not understand the differences, for if he understands the difference, then he is not with the weakness. You asked about the ‘الشَّهَادَاتِ’ testimonies for them. So establish the testimony for the sake of Allah (azwj), even if it is against your own-self, and the parents and the relatives in what is between you and them. So if you fear injustice against your brother, don’t (be part of it). And call to the Law of Allah (azwj), as He (azwj) has (placed those) in our (asws) recognition (Ma’rifat). The one who hopes would be Answered and do not barricade yourself by the fort of hypocrisy. And befriend the Progeny (asws) of Muhammad (saww) and do not speak of what reaches you from us (asws), and ascribe to us that ‘this is false’, and you may know something from us (asws) which is against it, for you do not know why we (asws) may have said it, and upon which perspective we may have described it. Believe in what I (asws) inform you (asws) and do not publicise what I (asws) have told you to conceal from what I (asws) inform you. It is from the obligatory right of your brother that you do not conceal anything from him which might benefit him in the affairs of the world and the Hereafter. And do not hold a grudge against him and not to hurt him, and answer his call when he calls you and do not leave him alone between him and his enemies from the people even though they may be closer to you than him, and support him in his illness. It is not from etiquettes of the ‘الْمُؤْمِنِينَ’ Believers, the defrauding, and the injuring, and the treachery, and the arrogance, and the vulgarities, and the immoralities, and the commanding for such things. So if you were to see the deformed Bedouin in legions (large armies), so wait for your relief (Al-Qaim (asws)), and for your Shiites, the believers, and when the sun rises, raise your vision to the sky and look at what Allah (azwj) has Done with the criminals. So I (asws) have explained to you all of this in summary. And send greetings upon Muhammad (saww) and his (saww) Progeny (asws), the righteous’.