Parsha: Vayeishev, "The Case of "Minhag Attiq"

"Every Ancient Minhag has a Root and a Source In Israel's Literature"

Who said this?

The Torah Temimah on Parshat Vayeshev (38:10): he wrote that not mourning a b'chor, firstborn son, is a "Minhag Ta'ut."

The Rema YD 374:11 terms this Minhag a "Minhag Ta'ut" - flowing from a Shu"t Rivash. As the TT says, all the acharonim remain silent. Nevertheless, the Targum Yonatan (TY), seems to be its source, reasoning that  it's because Yehudah named his second son Onan.

As the TT says, "It is known that all of his [TY] words flow from Braitot and Midrashim." Although we might not actually pasqen like this Targum Yonatan, he has a solid source. It's unsurprising that the Torah Temimah, who frequently searches for m'qorot for questionable minhaggim, was the Aruch haShulchan's son

We should also distinguish between ANY "Minhag b'alma" and a Minhag Attiq. A Minhag Attiq's source may have become more obscure over time since it seems to have greater peer approval.

Shalom
RRW