"Upon the first day of the week let every one of you lay by him in store, as God hath prospered him" (1 Corinthians 16:2). This is a personal responsibility enjoined on each believer (not couple) in the assembly. Paul has in view, though, "the collection for the saints" (verse 1) and wants to avoid a "gathering" when he comes to Corinth (verse 2). He teaches, therefore, that on the first day of the week the believers should contribute to a collective fund. These communications (Hebrews 13:16) are sacrifices, a part of our worship. Offering up spiritual sacrifices is the first priority of our gathering, but we should not conclude our gathering without these material offerings - whether by passing a basket or contributing to a box conveniently located in the place we meet.