Yet have I sent the brethren - The brethren referred to in 2 Corinthians 8:18, 2 Corinthians 8:22-23.
Lest our boasting of you - That you were disposed to contribute, and that you were already prepared, and that the contribution was ready.
Should be in vain - Lest anything should have occurred to prevent the collection. I have sent them that they may facilitate it, and that it may be secure and certain.
In this behalf - In this respect. That is, lest our boasting of you, in regard to your readiness to contribute to relieve the needs of others, should be found to have been ill-grounded.