Who were Lavan's "brothers" that he took with him to chase Yakov?
Rashi: They were his relatives. 1
Ramban: He took every mighty man from Charan.
Tosfos ha'Shalem (25:3, citing a Midras): They were dogs. 2
Ramban (Pasuk 46): They were also Yakov's relatives, for they are from Nachor's family. (The Pasuk there connotes that they are Yakov's brothers.) He did not want to confront Yakov with strangers, who would indulge in quarrels with Yakov and even steal from him.
This best explains (Pasuk 25) "Taka Es Echav" (PF).
How far apart was Lavan from Yakov when he (Lavan) set out to catch up with him? When did he catch him up?
Rashi: Lavan had left town, where they both lived, 1 to shear his sheep (which were three days away). When Yakov left town, it took three days for Lavan's men to inform him of the new developments. Meanwhile Yakov fled in the opposite direction, in which case Lavan was six days away from Yakov - and, as the Pasuk relates, he caught him up on the next day. 2
Riva, citing Chizkuni: Lavan returned to Charan (on day three), delayed three days (and gathered his "brothers"; refer to 31:23:1:2), and from there went seven days journey on the seventh day. We must say that even Lavan 4 rested on Shabbos. 5
Bechor Shor: Lavan traveled in four days (days four through seven) what Yakov traveled in seven days. 6
See Ba'alei Tosfos (Hadar Zekeinim).
See also Rashbam.
He comes to explain why Rashi says that Lavan went in one day what Yakov went in seven. If Lavan was to the east of Charan, and Yakov went west (towards Eretz Yisrael), he was more than seven days journey away! Perhaps he returned to Charan on the sixth day, looked for his Terafim and gathered his "brothers", and from there went seven days journey on the seventh day. Or, Lavan was roughly north or south of Charan, and Yakov was six days from him, and six days from Charan. Lavan went directly after Yakov (he knew that he was going to Eretz Kena'an). His brothers were already with him (refer to 31:19:151:1), and the informer had looked for the Terafim, and told Lavan that they were missing. (PF)
What was special about Har ha'Gil'ad?
Malbim: There, Lavan recognized Yakov's path, that he was heading for Har ha'Gil'ad. Until now, he did not know the path Yakov had taken.
Ha'Emek Davar: Yakov realized that he cannot push the children and flock to flee more (without resting), so he went off the road to rest in Har ha'Gil'ad, which is good pasture, and Lavan caught him there.
Why did Yakov not have Kefitzas ha'Derech?
Ohr ha'Chayim #1: Hashem wanted to show him that he did not need to flee. Even though Lavan caught him, he could not even speak to [harm] him. This was a bigger miracle, to show that Hashem will stop one with choice from harming Yakov.
Ohr ha'Chayim #2: Hashem caused that the make a Bris not to harm each other. Through this, Yisrael overpowered in the days of Kushan Rish'asayim (Sanhedrin 105a), and Rachel died on the way 1 , for the benefit of her children when they went to exile.
Through Yakov's words "Im Asher Timtza Es Elohecha Lo Yichyeh." Even without this, could Rachel not die on the way for her own words "Mesah Anochi" (30:1), or for selling a night's intimacy with Yakov, or for speaking up before her older sister? Four people died [solely] due to the sin [of Adam and Chavah, which came via] the snake (Shabbos 55b)! (PF)