He who forgets one thing that he has learned breaks a negative
commandment; for it is written (Deut. iv. 9), "Take heed to thyself ...
lest thou forget the things."

_Menachoth_, fol. 99, col. 2.

A proselyte who has taken it upon himself to observe the law, but is
suspected of neglecting one point, is to be suspected of being guilty of
neglecting the whole law, and therefore regarded as an apostate
Israelite, and to be punished accordingly.

_Bechoroth_, fol. 30, col. 2.

It is written (Gen. xxviii. ii), "And he took from the stones of the
place;" and again it is written (ver. 18), "And he took the stone."
Rabbi Isaac says this teaches that all these stones gathered themselves
together into one place, as if each were eager that the saint should lay
his head upon it. It happened, as the Rabbis tell us, that all the
stones were swallowed up by one another, and thus merged into one stone.

_Chullin_, fol. 91, col. 2.

Though the Midrash and two of the Targums, that of Jonathan and
the Yerushalmi, tell the same fanciful story about these stones,
Aben Ezra and R. Shemuel ben Meir among others adopt the
opposite and common-sense interpretation which assigns to the
word in Gen. xxviii. ii, no such occult meaning.

The psalms commencing "Blessed is the man" and "Why do the heathen rage"