Bi 比: see line 1.
Zi 自: (starting) from:
From the emperor to the common people…
(Mengzi 孟子, Lun Heng etc.)
Nei 內: its regular meaning is ‘inside, interior’, but in early texts it also refers to the women of the emperor (qiqie 妻妾, wife and concubines), the women’s quarters in the imperial palace, or women in general (漢語大字典 2nd ed., p. 111; 漢語大詞典, p. 995; 王力古漢語字典, p. 57):
Qing Feng of Qi was fond of hunting and drinking. He gave over the government [to his son] Qing She, and then removed with his harem and valuables to the house of Lu Pubie, with whom he drank, while they exchanged wives at the same time.
Zuozhuan 左傳 (tr. Legge, p. 541)
Even though the grammar and meanings in the sentence 比之自內 are pretty straightforward some translators are struggling to make sense out of it. For example, Lars Bo Christensen translates it as ‘Uniting with what comes from within is correct and good’, adding as a note ‘The question is what “from within” means. I don’t see any way you can connect physically with things from within, whether it be your body or an area.’ He totally misses the point that bi 比 is about people, persons, and that therefore a better translation of nei 內 is one that points to persons. His insertion of the words ‘with what comes’ is totally unnecessary and makes the translation not only wrong (these words are not in the Chinese original) but also more confusing.
In line 2 nei 內 might refer to allies that have a blood relationship with the wife of the king. Zi 自 means that the bond originates there.
Bonding via the empress.
The divination is auspicious.