Jacob 2:1 - 2:5
Jacob 2:1 The words which Jacob, the brother of Nephi, spake unto the people of Nephi, after the death of Nephi:
Words of Jacob to the Nephites sometime after the death of Nephi. (Probably at one of the Jewish Festivals in which all the people came together to comply with the Law of Moses.)
Jacob 2:2 Now, my beloved brethren, I, Jacob, according to the responsibility which I am under to God, to magnify mine office with soberness, and that I might rid my garments of your sins, I come up into the temple this day that I might declare unto you the word of God.
Jacob is at the Temple on this occasion to speak to the people. He is doing so to carry out his calling as a priest and a teacher. In addition, so the people could not say that they were not taught their duty to God by him and his fellow laborers in the priesthood.
Jacob 2:3 And ye yourselves know that I have hitherto been diligent in the office of my calling; but I this day am weighed down with much more desire and anxiety for the welfare of your souls than I have hitherto been.
The people know that Jacob has been persistent in carryout his calling. They know that from seeing him work on their behalf in the Church. But he is here on this occasion to talk about some things he has seen that bother him beyond what normally he sees amiss among them.
Jacob 2:4 For behold, as yet, ye have been obedient unto the word of the Lord, which I have given unto you.
They have been good at keeping the commandments that they have received so far.
Jacob 2:5 But behold, hearken ye unto me, and know that by the help of the all-powerful Creator of heaven and earth I can tell you concerning your thoughts, how that ye are beginning to labor in sin, which sin appeareth very abominable unto me, yea, and abominable unto God.
But he is seeing something that is alarming him greatly. He sees that they are with purpose and premeditation doing something that is very abominable to Jacob and to God. Jacob knows of the premeditation because the Lord has given him power to perceive their thoughts and intents of their hearts.