Chapter 5, Mishnah 6: Ten things were created at the twilight of Shabbos eve. These are (1.) the mouth of the earth, (2.) the mouth of (Miriam's) well, (3.) the mouth of (Bilaam's) donkey, (4.) the rainbow, (5.) the Mon–Manna, (6.) (Moshe's) staff; (7.) the Shamir, (8.) the writing, (9.) the inscription and (10.) the tablets (of the Ten Commandments).
The Simple Explanation
The Bartenura explains that this Mishnah discusses the end of the sixth day of Creation, Friday afternoon at twilight, immediately before Shabbos. That is when these ten miraculous items were created.
The ten items were (1.) the mouth of the earth which would swallow Korach and his band; (2.) the mouth of (Miriam's) well, which traveled together with the Jews throughout their 40 years in the wilderness, supplying them with water to drink; (3.) the mouth of (Bilaam's) donkey. On twilight of that Friday, it was decreed that when the time came, this donkey would have the ability to speak to Bilaam; (4.) the rainbow that appeared in the sky after the Great Flood. It was a sign of a covenant that Hashem would never again destroy the world with a flood; (5.) the Mon – Manna with which Hashem fed the Jewish Nation for forty years in the desert; (6.) (Moshe's) staff with which he performed the miracles at the time of the Exodus, which are described in the Torah; (7.) the Shamir, which was a sort of worm. It was able to slice through stone. It followed a path on the stone with a line drawn upon it. In this manner, the stones used to construct the altar in the Bais Hamikdosh were cut to size. It was prohibited for these stones to be hewn with metal implements; hence, this miraculous worm was necessary; (8.) the writing, meaning the form of the letters engraved upon the two tablets; (9.) the inscription upon the two tablets. The letters went entirely through the stones, yet they could miraculously be read from all four sides; and (10.) the tablets (of the Ten Commandments), which were made of sapphire.
