Midrash sa 2 Samuel 15:9: Ein Yaakov (Glick Edition), Shemot Rabbah & Midrash Tanchuma Buber

"Abshalom exalted himself with his hair," etc. Our Rabbis were taught Abshalom rebelled [against his father] through his hair, as it is said (II. Sam. 14, 25) And like Abshalom there was no man as handsome in all Israel, so that he was greatly praised. From the sole of his foot up to the crown of his head, there was no blemish on him. And when he shaved off [the hair of his head], and it was at the end of every year that he shaved it off because it was too heavy on him, he weiged the hair of his head at two hundred shekels by the king's weight. We are taught that this means, the weight was as one of those used among the Tiberians and Ziporians. Therefore was he hung by his hair, as it is said (Ib. 15, 9) And Abshalom happened to come before the servants of David. And Abshalom was riding upon a mule, and the mule came under the thick boughs of a big oak, and his head caught hold of the oak. It was taught in the school of R. Ishmael that he took his scissors and wanted to cut off his hair, but he at that moment saw Gehenna open under him [which frightened him] (Ib. 19, 1) And the king was much moved and he went up to the upper chamber of the gate and wept; and thus he said as he went, 'Oh, my son Abshalom, my son, my son Abshalom! I had died for thee. Oh, Abshalom, my son, my son!' But the king covered his face and the king cried with a loud voice. Oh, my son Abshalom, Oh! Abshalom, my son, my son!' These eight times, in which is mentioned My son for what purpose? Seven times it was for the purpose of bringing him forth from seven fires of Gehenna, the eighth one, was, according to some, for the purpose of connecting the head of Abshalom [which was cut off] to the body, and according to others it was for the purpose of bringing him into the future world. (Ib. 18, 18) Now Abshalom in his life-time had taken and reared up for himself the pillar, which is in the king's dale, for he said: 'I have no son to keep my name in remembrance; and he called the pillar after his own name; and it was called Abshalom's Monument, even until this day! What is the meaning of Abshalom has taken. Said Resh Lakish: "He purchased a bad bargain for himself." The pillar, which is in the king's vale. Said R. Chanina b. Papa: This [the word Aimek (vale)] means that if was caused by the deep council of the Universal King (Fol. 11) who said (Ib. 12, 11) I will raise up again this evil out of thy own house." Similarly is the following explained: (Gen. 37, 14) So he sent him out of the vale (aimek) of Hebron. Said R. Chanina b. Papa: "This was caused by the deep counsel of the Universal King, who said (Ib. 15, 13) Know of a surety that thy seed shall be a stranger in a land which is not theirs." (II Sam. 18, 18) For he said: 'I have no son.' Did he indeed not have a son? Behold, the passage says (Ib. 14, 27) And there were born unto Abshalom three sons and one daughter, whose name was Thamor. Said R. Isaac b. Abdimi: "The former passage means that he did not have a son fit to the royalty." R. Chisda said: "We have a tradition that whoever sets on fire his neighbor's crop, will not leave a son to inherit him, and Abshalom caused to set on fire the crop of Jo'ab, as it is written (Ib., ib., 30) He thereupon said unto his servants, 'See, Jo'ab's field is alongside of mine, and he hath barley there; go and set it on fire."

R. Chanina said: "The departure of the soul from the body is (Fol. 19) like a knotted rope passing through a loop-hole in the mast." R. Jochanan said: "Like ropes pulled through loop-holes in the board of a ship." (Fol. 29) R. Levi b. Chitha said: "He who takes leave of a dead body after burial shall not say, 'Go with peace,' but 'Go in peace.' However, if one takes leave of his living friend he should not say, 'Go in peace,' but 'Go with peace'; i.e., when one takes leave of a dead body he shall not say: 'Go with peace,' but 'Go in peace,' as it is said (Gen. 15, 15) But thou shalt come to thy fathers in peace (Beshalom); but when one takes leave of his living friend he should not say, 'Go in peace,' but 'Go with peace'; for Jethro, who said to Moses (Ex. 4, 18) Go with peace (Leshalom), Moses went and was successful; while David who said to Abshalam (II Sam. 15, 9) Go in peace, the latter went and hung himself." R. Levi said again: "He who goes out from the synagogue after prayer and enters the house of learning to study the Torah will be rewarded with permission to wait on the Divine Presence, for it is said (Ps. 84, 8) They go from strength to strength; each of them will appear before God in Zion."

“Moses went and returned to Yeter his father-in-law, and he said to him: Please, let me go and return to my brethren who are in Egypt and see if they are still alive. Yitro said to Moses: Go in peace [lekh leshalom]” (Exodus 4:18).
“He said to him: Please, let me go and return.” You find that everyone in whose regard “go in peace [leshalom]” is stated, he went and returned, and everyone in whose regard beshalom³David said to Avshalom: “Go in peace [beshalom]” (II Samuel 15:9), and he did not return. is written, he went and did not return. Yitro said to Moses: “Go in peace [leshalom],” and he went and returned.