Upon this rock
Mat 16:13-18a When Yeshua came into a section of Caesarea Philippi (see vs. 20, below), he asked his students, saying, “Who do men say that I the Son of Man am”? And they said, “Some say that thou art John the Matbil (a matbil is someone who acts as a witness at a ritual bath) some, Elijah, and others Jeremiah, or another of the prophets”. He saith unto them, “But who say ye that I am”? And Shimeon Kefa answered and said, “Thou art the Messiah of Israel, the Son of the living Elohim” (Psa 89:26-27; Pro 30:4). And Yeshua answered and said unto him, blessed art thou, Shimeon son of Jonah; for flesh and blood (Shimeon's flesh and blood was his father Jonah. "Flesh and blood" is an expression for a family member) hath not revealed it unto thee, but my Father who is in heaven. And I say also unto thee, that thou art Kefa.
“Kefa” is found in the Aramaic text. Compare John 1:42: Cephas or Kefa is Strong's #3710, and it means a "kidney shaped" stone. A kef was placed into a piece of cloth or a container and the lot was cast to make a difficult and final decision.
Mat 16:18b ...and upon this Decision Making Rock I will rebuild my Assembly (Isa 9:6; Jer 33:7-8; Zec 6:12-13; Act 15:16-17).
"Rock" in Hebrew is eben and is part of a Hebrew word pun. The rock used to determine a decision is also known in Hebrew as goral, teraphim, or Urim, Lev 16:8; Hos 3:4; Exo 28:30; Num 27:18-22; 33:54; Ezr 2:63. The judgments derived from the rock are referred to as the "oracles of God" (Heb 5:12; 1Pet 4:11).
The Hebrew word for "build" is banah, and is the second part of the Hebrew word pun, having the same root as eben. It means to build, rebuild, repair, or to obtain children (as in Luk 3:8).
The Hebrew word translated "church" is qahal, the entire assembly of Israel (Deu 18:16 & Act 7:38).