2 Corinthians 9:4 reveals the risk of shame if the Corinthians are unprepared, giving the motive behind sending the brothers in verse 3.

2 Corinthians 9:5 explains that the brothers go ahead to arrange the gift in advance, ensuring it is ready willingly — the immediate plan from verse 3.

2 Corinthians 7:14 recounts Paul's earlier validated boasting about the Corinthians to Titus; now he sends brothers to ensure that boasting about their readiness is not hollow.

2 Corinthians 8:17-24 identifies the brothers being sent and their purpose to prove the Corinthians' love — the same brothers and mission Paul mentions here.

2 Corinthians 8:6 shows Titus was urged to start the collection; now Paul sends brothers to see it completed, continuing the same project.

1 Corinthians 16:1-4 gives the original instructions for the collection; Paul now sends brothers to ensure those instructions are carried out.