From the Talmud

The work of the chariot

Whosoever prieth into the four things in the matter of the chariot in Ezekiel's vision--what is above, what is beneath, what is before, or what is behind--it were better for him if he had never been born.

The work or matter of the chariot, the Rabbinic term for the Vision of Ezekiel, ranks among the Arcana Judaica, which are not to be told save to the initiated.

References: Chaggigah, fol. 11, col. 2.

The four who entered the garden

Four men entered Paradise--these are their names:--Ben Azai, Ben Zoma, Acher, and Rabbi Akiva. Rabbi Akiva thus warned his companions: "When you come across pavements of pellucid marble, do not cry out 'Water! water!' for it is said (Ps. ci. 7), 'He that uttereth falsehood shall not dwell in my sight.'" Ben Azai looked and died; concerning him the Scripture says (Ps. cxvi. 15), "Precious in the sight of the Lord is the death of his saints." Ben Zoma looked and went out of his mind; of him the Scripture says (Prov. xxv. 16), "Hast thou found honey? eat only so much as is sufficient for thee, lest thou be filled therewith and vomit it." Acher cut the plants. Only Akiva departed in peace.

Rashi explains this by saying these men went up to heaven; but Maimonides much more rationally teaches that the Paradise or garden here is merely the retreat of profound philosophic meditation. These five intuitions were;--(1.) To know that there is a God; (2.) to ignore every other beside Him; (3.) to feel His unity; (4.) to love His person; and (5.) to stand in awe of His Majesty (see Vad Hachaz, chap. 4, sec. 19). Deep thought in these matters was spoken of by the Rabbis as _promenading in the garden_.

References: Chaggigah, fol. 14, col. 2.

The Book of Creation

Rabba once created a man (out of dust) and sent him to Rabbi Zira, who having addressed the figure and received no answer, said, "Thou art (made) by witchcraft; return to thy native dust." Rav Chaneanah and Rav Oshayah sat together every Sabbath-eve studying the book Yetzirah (i.e., the book of Creation), until they were able to create for themselves a calf (as large as a) three-year old, and they did eat thereof.

References: Sanhedrin, fol. 65, col. 2.