The net above the liver (Lev. 3:4, 10, 15), not the liver itself, was offered to God as the additional inward riches and the covering of this inward part. I believe that the liver was not required because it was not as small as the kidneys. The net above the liver is thinner than the fat surrounding the other parts. Of course, a net cannot be that thick. This means that the liver is not only bigger than the kidneys but also not as greatly protected by the fat. But regardless of how thin the net is, it is still the fat, and the fat is required as God's portion. This shows that we must have the riches of life to protect and to keep our experiences of the inward parts of Christ, which are so precious to God the Father. Within us we may have some experiences of the inward being of Christ, but we may not have that much of the riches of life. The net of the liver is thin, but it still functions as the additional inward riches to cover the liver.
The fat tail of the sheep or the lamb was also God's portion of the peace offering as additional riches (Lev. 3:9). With the sheep or the lamb, the riches of life as the fat tail are outside of the inwards. This indicates that the sheep or the lamb, according to the fat, is better than the ox because the ox's fat tail is not accepted. It is not tender enough.
The fat, the kidneys, the net above the liver, and the fat tail all indicate the riches of life inwardly with the tenderness, the smallness, and the preciousness. If we want to do a great work, make a great name, or have a great success right away, there can be no inwards in our offering to God. In other words, there can be no riches stored, concealed, or hidden inwardly. There can be nothing small, tender, and precious for God the Father.
I do not have the human language to adequately express this, but I would repeatedly refer you to the life of the Lord Jesus in the four Gospels. The life in the Gospels is sweeter and more tender than the life revealed in Acts. The life in the Gospels has more fat and inwards. I am not depreciating the life in Acts, but nothing can compare with the life of the Lord Jesus Himself revealed in the Gospels. The life in the Gospels is richer, more tender, more precious, and yet smaller. Which do you appreciate more—the three thousand saved on the day of Pentecost in Acts 2 or the three disciples on the high mountain with the Lord Jesus in Matthew 17? Do you want to be among the three or merely among the three thousand? Pentecostal preachers would prefer the three thousand. But what happened with the three thousand was not even as high in a certain sense as what took place with the five thousand who were fed by the Lord in the Gospels (Matt. 14:14-21). This shows that in the Gospels there are more inwards with more fat.
The portions of the peace offering which are God's portion become a sweet savor made by fire as food to God (Lev. 3:5, 11, 16). It is a sweet savor made by fire of the fat, the kidneys, the net above the liver, and the fat tail. These four items burned by fire produce the savor, and this savor is food to God (3:5, 11, 16). This is God's enjoyment of the peace offering. Whether or not we can offer such a peace offering depends upon our daily walk.