In Psalm 55:17, we read: “Evening and morning and at noon I utter my complaint and moan, and he hears my voice.”
John Calvin, commenting on this passage, remarks that these must have been the hours not only of sacrifice for ancient Israelites in this period, but of private prayer as well. The sacrifices have now been done away with; but the fact that God had instituted fixed times in the first place was a condescension to human weakness–that is, it had a practical aspect–and though the external rites of sacrifice “are no longer to be observed,” we still have “equal need of incitements” to overcome our lethargy and discharge our duty, and so “we should still prescribe,” he says, “certain hours to ourselves to be observed in prayer.” In the matter of the discipline of prayer, Calvin recommends that the “same principle” be applied in private (or “secret”) devotion as is applied in public devotion.
From the particular mention he makes of evening, morning, and noon, we are left to infer that these must have been the stated hours of prayer amongst the godly at that period. Sacrifices were offered daily in the temple morning and evening, and by this they were taught to engage privately in prayer within their own houses. At noon also it was the practice to offer additional sacrifices. As we are naturally indisposed for the duty of prayer, there is a danger that we may become remiss, and gradually omit it altogether, unless we restrict ourselves to a certain rule. In appointing particular fixed hours to be observed for his worship, there can be no doubt that God had respect to the infirmity of our nature, and the same principle should be applied to the secret as to the public services of devotion, as appears from the passage now before us, and from the example of Daniel, (Daniel 9:3.) Sacrifices are no longer to be observed in the Church, but as there remains the same indisposition on our part to the duty, and an equal need of incitements to overcome it, we should still prescribe certain hours to ourselves to be observed in prayer. He adds, that he would cry aloud, to denote vehemency of supplication, under the grief and anxiety of mind to which he was subjected. He intimates, that no extremity of present trouble would prevent him from directing his complaint to God, and cherishing a confident hope of deliverance.