Midrash su Ecclesiaste 4:9

(Bamidbar 27:18) "And the L-rd said to Moses: Take ("kach) for yourself Joshua the son of Nun": "kach" connotes "seizing," for a friend is acquired only with great difficulty — whence they ruled: One should acquire a friend for himself to learn Scripture with him, to learn Mishnah with him, to eat with him, to drink with him, and to tell his secrets to him. And thus is it written (Koheleth 4:9) "Two are better than one … (12) and the three-fold cord is not soon sundered." The Holy Spirit responded to Moses: Set up an interpreter for Joshua, and have him ask, expound, and teach rulings in your lifetime, so that Israel not say to him: "In the lifetime of your teacher you did not speak, and now you (suddenly) speak?" Others say: he (Moses) lifted him from the ground and placed him between his knees, and Moses and Israel would lift their heads to hear the voice of Joshua. And this is what it said: "Blessed is the L-rd, who gave Torah to Israel by the hand of Moses our teacher."

"Jacob is the chevel of His inheritance": "chevel" is a lot, as it is written (Psalms 16:5) "chavalim have fallen to me in pleasant places," and (Joshua 17:5) "And the lots of Menasheh fell — ten." (Ibid. 19:9) "From the chevel of the children of Judah was the inheritance of the children of Shimon": Just as a chevel (a rope) is three-fold, so Jacob was the third of the fathers, and he received reward over and against all of them. When Abraham was born, what is written? (Proverbs 17:17) "And a brother (Abraham) is born for affliction" (see beginning of # 311). When Israel was born, what is written? (Koheleth 4:9) "Better the two than the one." When Jacob was born, what is written (Ibid. 4:12) "And the three-fold cord is not soon sundered."