Book of the Garment

When you wish to wear this holy and pure name, fa[st] twenty-one days, take the pure golden tsits, write on it seventy-two letters from this name; then do what is written in it in holiness and in purity. And make a pure golden chain and go to the trough. Before you wear it pronounce this name to the trough with the prayer before sunrise. And examine yourself whether you purified or not. If you see a green figure in the trough [know] that there is sin on your hands. Then return and purify and fast twenty-one more days. Then go to the trough on the twenty-first day. Likewise, if in your prayer, as at first, you see a black figure, purify and fast again twenty-one more days, for you have not purified yourself. Then go in humility and give of your bread to the hungry and perform charity every day. Beware lest you incur wrath on yourself. A man will inform you and appear to you. Do not abandon him and do not deride him, and do not request greatness for yourself or for your mind or for silver and gold for you, and do not withhold your hand from the poor.

And you shall perform all of these [procedures] in the fear of God. Protect yourself well from any bad thing. And when you perform all of these [procedures] you should go out to the trough and say many prayers and supplications, and ask that you not fail again. Then speak this glorious name in fear and trembling. If you see the image of a lion of fire in the trough, know that you have succeeded wearing this holy name. Then you shall take the golden plate [tsits] on which this holy name is engraved and tie it around your neck and on your heart. Take care not to become more impure when it is on you, lest you be punished. Then you may do anything and you will succeed.

Source: MS Sassoon 290 + JTS MS ENA 2643.4.