What does "世俗之人 皆善人之同乎己" mean?

Today, I came across the following Chinese expression, which I do not completely understand.

世俗之人 皆善人之同乎己
세속지인 개선인지동호기

세상의 사람들은 모두가 다른 사람이 자기의 같은 것을 좋아 한다.

All people in the world like people who are similar to themselves.

I think I understand most parts of the above expression, but I do not understand the function of 乎 . Here is what I understand:

• 世俗之人 - the people of the world
• 皆 - all
• 善 - like
• 人之同 - people who are similar
• 乎 - to (Thanks, Taemin. See "comments" section.)
• 己 - themselves

Can someone explain to me the grammar of 人之同乎己?

UPDATE:

Taemin has explained to me that 乎 means "to" in the above expression, so 人之同乎己 means "people who are similar to themselves." Therefore, 同乎 (동호) could be generally translated as "similar to." The opposite meaning would be 異乎 (이호), which could be translated as "different from." The following is a sentence that uses 異乎 (이호) from King Sejong's "Hunmin Jeong-eum" (訓民正音).

國之語音 異乎中國 與文字 不相流通
국지어음 이호중국 여문자 불상유통

나라의 말 소리가 중국과 달라서 문자와 더불어 서로 통하지 못하다.

The sound of our language is different from China's, so the writing, as well, cannot correspond with each other.

• 國之語音 - The sound of our language
• 異乎 - is different from
• 中國 - China's
• 與 - likewise
• 文字 - the writing
• 不 - cannot
• 相 - each other
• 流通 - correspond

Many people may be interested in learning Korean, but not really interested in learning old Chinese sayings; however, here are a few modern examples of the 동 (同) and 이 (異) characters being used in speech today:

• 이동(異同)이 없다. - There is no difference.
  Notice that the characters for "different" (異) and "same" (同) combine to form a word that means "difference." I do not know why "different" wins out over "same," but it does. By the way, it does not matter if 동 (同) comes before 이 (異), as in 동이, it still means "difference."
  .
• 이국(異國) - a foreign country; a strange land
  .
• 이국(異國)적인 - exotic
  .
• 이상(異常)하다 - strange; different (異) from the ordinary (常)
  .
• 동반(同伴)하다 - to accompany
  .
• 동생(同生) - a younger brother or sister
  .
• 동시(同時)에 - at the same time
  .
• 동의(同意)하다 - to agree with; to have the same (同) opinion (意)
  .
• 동포(同胞) - fellow countrymen; brethren
  .
• 동행(同行)하다 - to travel together; to go in company with
  (In a restaurant) 동행은 세 사람입니다. (We are a party of three.)