Why is there no explicit commandment in the New Testament concerning the prayers of the canonical hours?

The Holy Bible is not a book of regulations; otherwise, it would have set out exactly how the bishop, priest, and deacon are to be ordained, and how the sacrament of marriage should be performed. Many things were delivered orally (2 John 12). And if it were to contain such specific commandments about the canonical hours, any believer unable to practice one of these prayers due to circumstances would feel that he is breaking a divine commandment.

Tertullian mentions examples in the book of Acts (2:1, 5; 10:9; 3:1) where he observes the absence of any explicit commandments to pray the canonical prayers, although these prayers were steadfast principles in the life of the Church from its inception. He goes on to say, “Albeit these practices stand simply without any precept for their observance, still it may be granted a good thing to establish some definite presumption, which may both add stringency to the admonition to pray, and may, as it were by a law, tear us out from our businesses unto such a duty.”¹²⁰

And in the same chapter he stresses the necessity of morning and evening prayers in addition to the other prayers, saying, “in addition to our regular prayers which are due, without any admonition, on the entrance of light and of night.”¹²¹

He also mentions the midnight prayer indirectly when he considers the status of a woman who marries a non-believing man, and questions how it is that she can arise from her bed at midnight to pray, thus casting her pearls before swine [i.e., praying before her unbelieving husband] (Matt. 7:6).¹²²