1 Corinthians 10:10

Fourth, the Israelites grumbled frequently against the Lord during the wilderness wanderings. Moses recorded 10 separate instances in Exodus and Numbers. However the occasion Paul had in mind was when God sent fire that consumed some of the people on the edge of the camp (Numbers 11:1-3). Here Paul added that God executed His wrath by using an angel, a fact that Moses did not mention in Numbers. The Septuagint translators used the same term, "the destroyer" (Gr. olothreutes), to describe the angel who executed the Egyptians’ first-born on the night of the Exodus (Exodus 12:23; cf. Hebrews 11:28).

Many instances of the Corinthian Christians’ dissatisfactions with God’s provisions for them come out in this epistle. Not the least of these was their rejection of some of the Lord’s servants who had come to minister to them because they preferred some others (1 Corinthians 1:10 to 1 Corinthians 4:21). They did not appreciate Paul’s earlier instruction to break off company with idolaters and the sexually immoral (1 Corinthians 5:9-11). Another example is the impatience of the "strong" in the church with the "weak" (1 Corinthians 8:1-3). Grumbling is a telltale sign of selfishness and discontent with what God has given us.