הרב שמעון הפקולי

Shimon HaPakuli was a tanna, remembered chiefly for arranging the eighteen blessings of the Shemoneh Esrei in their proper order before Rabban Gamliel at Yavneh. The Gemara in Berachot (28b) and Megillah (17b) brings this teaching, noting that he set the blessings in sequence in the presence of Rabban Gamliel.

The Gemara in Megillah (18a) addresses an apparent difficulty: since the hundred and twenty elders, among them several prophets, had already established the prayer in order, what did Shimon HaPakuli arrange? The answer given is that the blessings had been forgotten, and he restored them and set them once more in their proper order. It is in this same setting at Yavneh that Rabban Gamliel asked the Sages whether anyone could compose the blessing concerning the heretics, and Shmuel HaKatan stood and composed it.