Midrash su Isaia 50:2

Rabin b. R. Ada in the name of R. Isaac said: "Whoever frequents the synagogue [daily] and misses one day, the Holy One, praised be He! inquires about him; for it is written (Is. 50, 10.) Who is among you, that feareth the Lord, that hearkeneth to the voice of His servant? Though he has walked in darkness and had no light, let him trust in the name of the Lord; i.e., if he went to perform a meritorious deed [and was therefore absent from synagogue] there will be light unto him; but if his absence is due to personal business, then there will be no light unto him for he should have placed his trust in God." R. Jochanan said: When the Holy One, praised be He! enters the synagogue and does not find ten [men] present, His anger is immediately stirred, as it is said (Is. 50, 2.) Why did I come and no man was there, did I call with none to answer."

Rabbi Pinḥas said in the name of Rabbi Hoshaya: “While the king was at his feast,” while the King of kings, the Holy One blessed be He, was at His feast, in the firmament—He arrived early,²⁷⁸He arrived early for the giving of the Torah. as it is stated: “It was on the third day when it was morning” (Exodus 19:16). [This is analogous] to a king who decreed: On such and such day I will enter the province. The residents of the province slept through the night and when the king arrived, he found them asleep. He positioned trumpets, horns, and a shofar, the governor of that province awakened them and brought them out to meet the king, and the king walked before them until he reached his palace. So too, the Holy One blessed be He arrived early, as it is stated: “It was on the third day when it was morning,” and it is written: “For on the third day, the Lord will descend before the eyes of the entire people” (Exodus 19:11). Israel slept through that entire night because sleep during [the season of] Shavuot is pleasant and the night is short. Rabbi Yudan said: Not even a flea stung them. The Holy One blessed be He came and found them asleep. He began positioning trumpets; that is what is written: “It was on the third day when it was morning, there was thunder and lightning” (Exodus 19:16), and Moses was awakening them and taking them out to meet the King of kings the Holy One blessed be He. That is what is written: “Moses took the people out of the camp toward God” (Exodus 19:17). The Holy One blessed be He was walking before them until He reached Mount Sinai, as it is written: “The entire Mount Sinai was smoking [because the Lord had descended]” (Exodus 19:18). Rabbi Yitzḥak said: This is why He taunted them through Isaiah, as it is stated: “Why have I come and there is no man, I called and there is no one to answer? Is My hand insufficient for redemption?” (Isaiah 50:2).