Bojjhasutta 3.5

3.5

Evaṃ upavuttho kho, bojjhe, aṭṭhaṅgasamannāgato uposatho mahapphalo hoti mahānisaṃso mahājutiko mahāvipphāro.

The observance of the sabbath with its eight factors in this way is very fruitful and beneficial and brilliant and bountiful.