1 Corinthians 10:18

Behold Israel after the flesh: have not they that eat the sacrifices communion with the altar?

'Behold' -'Look at' (NASV)

'Israel after the flesh' -'the nation of Israel' (NASV) Which implies that an "Israel after the Spirit" exists. (Galatians 3:28; Galatians 6:16; Romans 2:28)

'eat the sacrifices communion with the altar?' -'the language "eat the sacrifices" refers to the meal that followed the actual sacrifice, in which they together ate portions of the sacrificial food. (Deuteronomy 14:22)' (Fee p. 470)

'I.E. PARTICIPATION IN THE SACRIFICIAL FEAST CONSTITUTES FELLOWSHIP IN THE SACRIFICE.' (Gr. Ex. N.T. p. 865)

Paul now will proceed to apply the principles learned in 16-18, but before he does this, he anticipates their arguments.

'Since Paul has been arguing that there IS religious significance to the Lord's Table and to the sacrificial meals of Israel, he must now qualify their argument in light of that reality.' (Fee p. 471)