Komentarz do Rodzaju 38:30

אשר על ידו השני THAT HAD THE SHINING RED THREAD UPON HIS HAND — The word יד is written here four times corresponding to the four acts of sacrilege which Achan, who was a descendant of Perez, committed with his hand. Others say these correspond to the four things which he took with his hand of the spoil of Jericho: a Babylon garment, two hundred shekels, and a wedge of gold (Genesis Rabbah 85:14).

זרח. On account of the woolen thread which was red in colour. The word זרח basically means red, such as the colour of the sun at the time it rises and when it sets. If it does not appear red during the day this is because of the excess amount of light during those hours making it impossible for us to notice the red colour behind all that light. We find confirmation of the redness of the sun in Kings II 3,22 when the Moabites were deceived by believing that the rising sun’s redness represented blood remaining from a violent battle and they thought they could then simply move over to the camp of the Israelites and pick up the spoils.

זרח, she named him in commemoration of the red string she had wound around his hand. This colour symbolises a warning.

Corresponding the four bans ... corresponding to the four things that he took... I.e., the four things Achan took, which were: a cloak from Shinar, two chunks of silver worth 200 shekels, making three, and a strand of gold, making four. Re’m objects: Sanhedrin 43b mentions a view that he violated three bans, and a view that it was five — four in Moshe’s time and one in Yehoshua’s. Either way, it was not four. Re’m answers: According to Bereishis Rabbah, [which Rashi is citing, this verse] deals only with the four bans of Moshe’s days. But this is incorrect because Bereishis Rabbah lists the four bans: those of Amalek, Sichon and Og, Yericho, and Midian. This is three in Moshe’s days and one in Yehoshua’s. There is a lengthy answer to this. But the Maharsha emends the text in Sanhedrin 43b to read: “Rabbi Yochanan said it was four bans...” [Accordingly, Rashi was following this view.] (Nachalas Yaakov)

ויקרא שמו זרח, “he named him Zerach”. He was reddish skinned, and the word זרח appears in that sense in Kings II 3,22.

ויקרא שמו זרח AND HIS NAME WAS CALLED ZARAH — (bright, shining), because of the bright colour of the scarlet thread.

Because of the bright color of the scarlet thread. [Rashi knew this because this way Zorach] is like Peretz, who was named after what happened.