Ezra 6:19

And the children, of the captivity kept the passover Now they were newly delivered out of their bondage in Babylon, it was seasonable to commemorate their deliverance out of their bondage in Egypt. Fresh mercies should put us in mind of former mercies. We may suppose that they had kept the passover, after a sort, every year since their return; for they had an altar and a tabernacle. But they were liable to frequent disturbances from their enemies, were straitened for room, and had not conveniences about them, so that they could not do it with due solemnity, till the temple was built; and now they made a joyful festival of it, it falling out in the next month after the temple was finished and dedicated.