They Who Lead
"On the way a man wishes to follow," say our Sages, "they lead him."
The Torah source for this is the account of how the heathen prophet Bilaam decided to accept the invitation of the Moabite king Balak to curse the Israelites whom he saw as a threat to his land. When Bilaam first sought direction from G-d he was told not to go with Balaks emissaries and not to curse the blessed Israelites (Bamidbar 22:12). Bilaam reluctantly informed the emissaries that he was unable to comply with their wish but in his heart he longed for the opportunity to earn the great reward promised him. This desire produced the result that he was informed in a second nocturnal vision that he could go with Balaks emissaries (ibid. 22:20).
Maharsha calls attention to the use of the plural term "they" in the above mentioned statement about being led in the direction one wishes to follow. He explains it according to the principle, often mentioned in his writings, that every human act, statement and even thought creates an angel, for good or evil. Man indeed has free will, for "everything is determined by Heaven except fear of Heaven" (Ketubot 30a). It is "they", the angels created by the exercise of this free will, who then lead him along the path he has chosen to follow.
Bilaam had such a strong desire to go with Balaks emissaries and to curse the Israelites that G-d sent him the angel created from that desire to lead him along the path he had chosen by telling him that he could go.
The same idea finds expression in a passage of the Prophets (Yeshayahu 48:17) and the Sacred Writings (Mishlei 3:34). In each of these sources, explains Maharsha, it is the angels created by human desire who lead man towards the destination he has chosen.
The prime responsibility for executing a convicted murderer was delegated by the Torah (Bamidbar 35:19) to the close relative who is his "blood avenger". The one exception is the case of a father who murdered his son. The brother of the victim cannot be assigned this role because of the respect he owes his father. Should the victim have a son, however, he may be appointed as the executioner of his grandfather.
Rashis explanation that a grandson is not obligated in the mitzvah of honoring his grandfather is the springboard for a major discussion in halachic literature. Those commentaries who contend that a grandson is obligated to honor his grandfather draw support from a passage in the Torah (Bereishet 46:1) which relates that when Yaakov reached Beersheba on his way to a reunion with Yosef in Egypt he offered sacrifices to "the G-d of his father Yitzchak". Rashi there explains that only Yitzchaks name is mentioned and not that of Yaakovs grandfather Avraham, because greater honor is due a father than to a grandfather. It is on this basis that Rema (Shulchan Aruch Yoreh Deah 240:24) rules that there is an obligation to honor a grandfather but that honor to a father is a greater obligation. (Only if there is a conflict between the two obligations would this matter. Otherwise the honor due to a grandparent is equal to that due to a parent.)
In Mesechta Sota (49a) there is the incident of Rabbi Acha bar Yaakov who asked the grandson he raised to give him a drink of water only to be reminded that he was only a grandson and therefore not obligated to honor him like a son. This is cited as support for the opposing position although a difference may be made between a fathers father and a mothers father as is the case in that gemara.
For further research on this subject see the Responsa of Rabbi Akiva Eiger (Vol. I, No. 68) and the Responsa of Shvut Yaakov (Vol. II, No. 94)