1)
What is the meaning of "Ba'u Ad Toch ha'Bayis Lokchei Chitim"?
1.
Rashi: They came with merchants buying wheat. R. Yeshayah - they were together in the plot to kill Ish Boshes.
2.
Mahari Kara, Targum Yonasan: They came as if they came to buy wheat.
3.
Malbim: They had previously entered a house for wheat merchants, and killed the owner.