1 Corinthians 10:18

Behold Israel after the flesh: are not they which eat of the sacrifices partakers of the altar? (KJV)

Then: Paul refers to the Israelites' normal practice of sacrificing offerings to the Lord. Commentators take this as a good example (not the part about their sacrificing to Baal) which then contrasts with the unworthy actions of Corinthians' offerings to the temple gods. The verse is the third of six rhetorical questions noted by Baker (p. 147). It pushes (or draws) knowledge conscious Corinthians to evaluate their own actions.

Now: When today's believers turn to the idea of bringing gifts to the altar, they are also drawn into an evaluation of their gifts - worthy or unworthy? Gifts to the Lord or thoughtlessly wasted on anther altar?

Extra source: Cornerstone Biblical Commentary 1 Corinthians (William Baker), 2 Corinthians (Ralph Martin & Carl Toney), ed. by Philip Comfort. Carol Stream: Tyndale House Publishers, c2006.