What are the connotations of "Menuchah" and "ha'Aretz"?
Rashi: "Menuchah" is referring to Yisachar's portion of land, which was blessed and fruit-producing. 1
Rashbam, Riva: Yisachar saw that the Menuchah of staying home 2 and working on the land was preferable to traveling long distances (like his brother Zevulun), and that the land was productive. 3
Targum Yonasan: He saw the restfulness of Olam ha'Ba and that his portion in the land was fruitful.
Ohr ha'Chayim: He saw the supreme rest, and contemplated all worldly pleasures, the sweetness of the matter is only due to the body, an empty Keli that stands to be filled. The Creator made nature that he cannot delay empty. He pines and longs for food to fill his stomach. When he is satiated with the same food, he despises it like evil - "Pitecha Achalta Seki'enah" (Mishlei 23:8). Also if one craves a beautiful creation, proper investigation shows that the beauty is mere appearance of substance. Man's form is built of flesh and skin, and all his beauty is from it. If he contemplates, he will despise approaching human flesh; it is all fantasy. The true good is of the upper world [to come], which is called "Menuchah."
Malbim: He saw that it is better to stay home than to travel far for business, for engaging in Chochmah and Torah requires serenity. He saw that working the land is pleasant, and chose it.
Ha'amek Davar: He refused to supply soldiers, for he saw that Menuchah, i.e. engaging in Torah, is good. One who goes to the army cannot engage in Torah, and is forced to leave his land. 4
What was Yaakov referring to when he said, "va'Yet Shichmo Lisbol... "?
Rashi #1 and Targum Yonasan: Due to the bountifulness of Yisachar's land, 1 he will take on the responsibility of teaching Torah, giving Halachic rulings and arranging the calendar. 2
Rashi #2 (citing Targum Onkelos): They bent their shoulder to do battle and to conquer the towns of other nations, and the enemy that remained paid them taxes.
Rashbam: He bent his back to accept the yoke of the kings of Yisrael. 3
Seforno: When he saw the restfulness of spiritual attainment, and that his land is able to sustain him without pain, he bent his shoulder to take on the yoke of Torah and the yoke of communal leadership. 4
Riva, Malbim: He accepted the yoke of working the land [for it is better than commerce; refer to 49:15:1:2, and 49:15:1:5].
Ohr ha'Chayim: He bent his shoulder to accept pain of this world.
Ha'amek Davar: In place of supplying soldiers, 5 he bent his shoulder to bear the Da'as of all Yisrael, whatever they will impose on him for the need of the country.
Targum Yonasan: And the restfulness of the world to come.
Rashi: At one stage, they actually provided two hundred heads of Sanhedrin (as the Pasuk records in Divrei ha'Yamim I 12:33), whose instructions the people followed.
Rashbam: And to give them one tenth of the annual harvest (See Shmuel I 8:14-15).
Seforno: As the Gemara says (Mo'ed Katan 6a), 'When there is a Talmid Chacham in town, all matters of communal concern are placed upon him.' The other tribes - the workers - have to 'pay' the Talmid Chacham by working for him, as the Gemara states (Yoma 72b) 'The people in the town are obligated to do the work of the Talmid Chacham.'
What is "l'Mas Oved"?
Riva: He gives Terumos and Ma'aseros to Kohanim and Leviyim, and taxes to the king. 1
Ohr ha'Chayim #2: He made himself like a tax that is given. So he gave himself to do Avodas ha'Kodesh, which is sweet.
Ohr ha'Chayim #3: All the creations will give to him a tax to finance a Ben Torah, and serve him, like we find that Zevulun worked for Yisachar, and so in all generations.
Malbim: From the grain, he gives taxes to the king.
Ha'amek Davar: He paid a large tax to soldiers from other Shevatim 2 and costs of war. Even though Tosfos (Chagigah 8a) says that "l'Mas" is servitude, and not money, supplying needs of the war is called Avdus.
