1. Someone I know recently sent me what’s written below. Growing up I always learned that if there’s a Minhag that the Jews took upon themselves then it becomes Halacha. I’m not sure if they consider it a Halacha from the Torah or from the Sanhedrin, but nevertheless it becomes Halacha, that’s what I was taught. I’ve heard you mention before that a Minhag is of less importance than a Halacha and there’s more room to not keep the Minhag if someone isn’t in the mood or if it’s an inconvenience. Can you explain your perspective and Psak? Thank you!

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the phrase “the custom of Israel, is Torah” appears about 350 times in Torah literature.
the phrase “the custom of our ancestors, is Torah” appears about 177 times
“The custom of Israel is law” appears a few times in the literature
The Rambam wrote in his novella (Pesachim 7:2): “And the custom of our ancestors is Torah.”

The Ritva wrote in his novella (Pesachim 15:1): “And the custom of our ancestors is Torah, and our Rabbi Meshulam replied to the R.T. [  both from France, 12th century],” and he too followed the Rambam ‘s path ; 3) Ras HaNahash wrote in his commentary on Pesachim (10:13): “And the custom of our fathers is Torah,” and in his commentary on Rosh Hashana (10:14) he added: “And the custom of our fathers is Torah and cannot be changed .”
4) HaTur (O”C 1955) wrote: “And the custom of our fathers is Torah and cannot be changed,” and he also wrote in the Law of Yom Kippur, section 13; 5) HaGor wrote: “The custom nullifies the law, and the custom of our fathers  is Torah” (cited in Khirbet Yusuf, section 14); 6) Ramoh – Rabbi Moshe Isserlis wrote in Darchi Moshe HaKatzer (33:20): “The custom of our fathers  is Torah,” and he repeats this in two other places in his book (ibid. 33:25; Rambam, section 14). However, in section 16 he wrote: “And the custom of Israel  is Torah”.

“The custom of Israel  is Torah,” and it is found many times, and here are just a few examples: 1) “Magen Avraham” (67:16) it is said: “And I say the custom of Israel is Torah”; 2) “Peri Magdim” (O”H, Eshel Avraham, 50) it is said: “And the custom of Israel is Torah”; 3) “Baraki Yosef” (Yod”D, 50) it is said: “And the custom of Israel is Torah”; 4) “Pitchei Teshuvah” (Yod”D, 50) it is said: “And the custom of Israel is Torah”;
Rashba wrote in Responsa (1:9) that a custom that exists even among old men or old women should not be abolished, since “necessarily” it has an origin that goes back to Moses.
Israel Hagiz wrote (Responsa Hilchot Ketano 1:9), “The Blessed One will certainly not allow a false custom to become known aamong all His people, and therefore a custom that has become widespread is certainly true.”

According to the Hatam-Sofer, every custom is from the Torah, from the law of a vow (Yod. 17).