Dictionary of Biblical Words:
This expression refers to the fact, that the Church which is Christ’s body (Eph. 1:23), instead of being one (John 17; Eph. 4:2, &c.), is divided and split up into above 1,000 sects and parties. Of course the fact that all believers form one body cannot be destroyed (hence the “ruin of the body” would be incorrect), but the outward expression of this unity by a once united assembly or Church is gone entirely: hence the expression.
Concise Bible Dictionary:
Two words are principally employed for this word. One is sela, “an elevation of strength, immovable:” used symbolically for Jehovah as the rock of His people: “Jehovah is my rock and my fortress” (Psa. 18:2). He hath “set my feet upon a rock, and established my goings” (Psa. 40:2).
The other word is tsur, a rock, generally sharp and precipitous, “a place of shelter and security” “Lead me to the rock that is higher than I”; Thou art “my father, my God, and the rock of my salvation.” “My God is the rock of my refuge” (Psa. 61:2; Psa. 89:26; Psa. 94:22).
In the New Testament anyone who heard and did the sayings of the Lord is compared to a man who built his house upon the rock which nothing could shake (Matt. 7:24-25; Luke 6:48). The Lord said, “Thou art Peter (πέτρος), and upon this rock (πέτρα) I will build My church.” The church is being built upon what Peter confessed, Christ Himself, the Son of the living God (Matt. 16:16-18; compare 1 Cor. 3:11; 1 Cor. 10:4).
Strong’s Dictionary of Greek Words:
Meaning:
feminine of the same as 4074; a (mass of) rock (literally or figuratively)