Imam al-Jawad (peace be upon him): Ali ibn Mahziyar said: Imam al-Jawad (peace be upon him) wrote a letter to him, and I read his letter to him on the road to Mecca. He said: "What I have made obligatory in this year [and this is the year two hundred and twenty] is only for one meaning among the meanings [of the verse]. I do not like to explain the whole meaning of it, because I fear it will be spread, and I will soon explain some of it (the meaning) to you, if Allah the Exalted wills. Indeed my Shia [whose well-being I ask from Allah], or some of them, have fallen short in their obligations. I came to know of this. I wished to purify them and nurture them [by this act I did this year of ordering them to pay khums]. Allah the Exalted said: خُذْ مِنْ أَمْوالِهِمْ صَدَقَةً تُطَهِّرُهُمْ وَ تُزَکِّیهِمْ بِها وَ صَلِّ عَلَیْهِمْ إِنَّ صَلاتَکَ سَکَنٌ لَهُمْ وَ اللهُ سَمِیعٌ عَلِیمٌ * أَ لَمْ یَعْلَمُوا أَنَّ اللهَ هُوَ یَقْبَلُ التَّوْبَةَ عَنْ عِبادِهِ وَ یَأْخُذُ الصَّدَقاتِ وَ أَنَّ اللهَ هُوَ التَّوَّابُ الرَّحِیمُ. وَ قُلِ اعْمَلُوا فَسَیَرَی اللهُ عَمَلَکُمْ وَ رَسُولُهُ وَ الْمُؤْمِنُونَ وَ سَتُرَدُّونَ إِلی عالِمِ الْغَیْبِ وَ الشَّهادَةِ فَیُنَبِّئُکُمْ بِما کُنْتُمْ تَعْمَلُونَ [Take alms out of their property, you would cleanse them and purify them thereby, and pray for them; surely your prayer is a relief to them; and Allah is Hearing, Knowing. Do they not know that Allah is He who accepts repentance from His servants and takes the alms, and that Allah is the Oft-returning, the Merciful. And say: Work; so Allah will see your work and (so will) His Messenger and the believers; and you shall be brought back to the Knower of the unseen and the seen, then He will inform you of what you did]. I have not made it (khums) obligatory upon them every year, nor do I make anything obligatory upon them except the zakat which Allah has made obligatory upon them. This year I have only made khums obligatory upon them on gold and silver upon which a year has passed since acquiring them. I have not made it (khums) obligatory in clothes, nor in vessels, nor animals, nor servants, nor profit gained in trade, nor estates — except for one estate whose matter [the one estate upon which I made khums obligatory] I will soon explain to you. [And this act] is a lightening from me upon my Shia and a favor from me upon them, because the ruler steals their wealth, and for that reason there are afflictions in their persons."