Rashi (1040-1105) is considered by many people to be the greatest Bible commentator. It is the first Bible commentary learnt by many Jewish Children. Both children and adults enjoy the commentary because Rashi was an excellent writer, and his commentary is filled with fascinating stories, called midrashim, which Rashi apparently believed were actual facts. He states several times that he is giving the plain meaning of the biblical text, but many people, especially scholars, recognize that while he may have considered his midrashic-stories true, rationalist would disagree.
For example, in his commentary on Genesis 9:10, he writes that Noah saved demons in his ark. On Genesis 32:4, he says that Jacob used actual angels as messengers whom he sent to his brother Esau. Rashi’s grandson was infuriated by this commentary.
Rashi’s grandson Rabbi Samuel ben Meir (also known as Rashbam, about 1085–1174), the son of one of Rashi’s daughters, wrote his Bible commentary, largely, with the goal in mind to liberate people from this use of midrash, and to show his objection to Rashi’s frequent use of it.
A good example is Rashbam’s interpretation of Genesis 1:5. According to the Torah, as explained by Rashbam in his commentary to Genesis 1:5, the day begins in the morning. Scripture states that God did creative acts during the day and this was followed by evening and morning, the end of the day. We might add that it was most likely during the Babylonian exile after the temple was destroyed in 586 BCE that the Israelites accepted the Babylonian practice of starting the day at night. While the beginning of the day changed for other purposes, it did not change the temple service. When the second temple was constructed, the day began in the morning as in the past, and the first sacrifice was offered in the morning.
Lockshin notes that Rashi’s Torah Commentary is the primary focus of Rashbam’s own commentary. Of some 650 remarks in Rashbam’s commentary to Genesis, for example, only about thirty-three percent concern issues not relevant to Rashi. Of the remaining two-thirds, in only about eighteen percent does Rashbam feel Rashi is correct, and in just over forty-eight percent he is in disagreement with him, consistently criticizing him for substituting derash for peshat – the very thing Rashi declared he would not do.
Rashbam criticized his grandfather Rashi harshly for inserting midrashic explanations into his commentary and not sticking to the plain meaning of the biblical passages. In his commentary on Genesis 37:1, he told his readers that he upbraided his grandfather for the way he explained the Torah, and that Rashi assured him that he agreed with him. Rashi told him that if he had years to write new explanations, he would write a book in the way that Rashbam wrote his commentary.
Genesis 49 has statements that the patriarch Jacob made to most of his sons. Rashi wrote that verse 17 refers to the judge Samson. Rashbam commented that this view was absolutely wrong and not the plain meaning of the text which was not speaking about a man who would not be born for centuries. Rashbam angrily writes that anyone who thinks that this passage is speaking about Samson doesn’t know how to understand the Torah.
In Deuteronomy 15:18, Scripture mandates that slave owners must give their Hebrew slaves gifts when they set them free. The Torah continues: “It should not seem hard to you … because he gave you double the service of a hired man.” Rashi (based on Midrash Sifrei) proposes that Scripture’s “double” means that Hebrew slaves work day and night, while hired employees works only during the day; the nighttime work is when the master gives the slave a Canaanite slave so that he can have children from the union that would belong to him as slaves. Rashbam calls this interpretations “foolish” and “vapor.” The plain meaning of the verse, he says, is that the “master” should not feel bad in having paid for slaves twice, when he purchased slaves and now when he must also give them gifts.
The eleventh century rationalist Abraham ibn Ezra, who lived around the same time, took a similar view of Rashi’s commentary. He wrote mockingly: Rashi states that he translates the Torah according to its plain meaning and he is correct — one time out of a thousand.
 M. I. Lockshin, Rabbi Samuel ben Meir’s Commentary on Genesis, (Jewish Studies, The Edwin Mellen Press, 1989). It is significant to note that although Rashbam railed against the insertion of derash into a biblical commentary, his own commentary was frequently adulterated, as was Targum Onkelos and others, by the improper insertions of derash by later hands. See, for example, Deuteronomy 2:20, 3:23, 7:11, and 11:10 in A. I. Bromberg, Perush HaTorah l’Rashbam (Israel, Tel Aviv, 1964), 201, note 25; 202, note 111; 206, 7, note 9; and 210, note 3.
 Lockshin,,pages 391–99.