Kethuboth_, fol. 77, col. 2.

If a man says to a woman, "Thou art betrothed to me after thirty days,"
and in the interim another comes and betroths her, she is the second
suitor's.

_Kiddushin_, fol. 58, col 2.

If one finds a scroll, he may peruse it once in thirty days, but he must
not teach out of it, nor may another join him in reading it; if he does
not know how to read, he must unroll it. If a garment be found, it
should be shaken and spread out once in thirty days, for its own sake
(to preserve it), but not for display. Silver and copper articles should
be used to take care of them, but not for the sake of ornament. Gold and
glass vessels he should not meddle with--till the coming of Elijah.

_Bava Metzia_, fol. 29, col. 2.

Rabbi Zira so inured his body (to endurance) that the fire of Gehenna
had no power over it. Every thirty days he experimented on himself,
ascending a fiery furnace, and finally sitting down in the midst of it
without being affected by the fire. One day, however, as the Rabbis
fixed their eyes upon him, his hips became singed, and from that day
onward he was noted in Jewry as the little man with the singed hips.

Ibid., fol. 85, col. 1.

An Arab once said to Rabbah bar Channah, "Come and I will show thee the
place where Korah and his accomplices were swallowed up." "There," says
the Rabbi, "I observed smoke coming out from two cracks in the ground.
Into one of these he inserted some wool tied on to the end of his spear,
and when he drew it out again it was scorched. Then he bade me listen. I
did so, and as I listened heard them groan out, 'Moses and his law are
true, but we are liars.' The Arab then told me that they come round to
this place once in every thirty days, being stirred about in the
hell-surge like meat in the boiling caldron."

_Bava Bathra_, fol. 74, col. 1.

Rabbi Yochanan, in expounding Isa. liv. 12, said, "The Holy One--blessed
be He!--will bring precious stones and pearls, each measuring thirty
cubits by thirty, and polishing them down to twenty cubits by ten, will
place them in the gates of Jerusalem." A certain disciple contemptuously
observed, "No one has ever yet seen a precious stone as large as a small
bird's egg, and is it likely that such immense ones as these have any
existence?" He happened one day after this to go forth on a voyage, and
there in the sea he saw the angels quarrying precious stones and pearls
like those his Rabbi had told him of, and upon i