His statement, “and what is recommended”: what is recommended is the same as what is prescribed by the sunnah: that which one is commanded to do, but not in a binding manner. If one is commanded to do it in a binding manner, then it is obligatory.
The ruling on what is recommended is that the one who does it in compliance with the command is rewarded, while the one who leaves it is not punished. However, the reward for what is recommended or prescribed by the sunnah is less than the reward for what is obligatory, as established by both textual and rational evidence.
As for the textual evidence, it is Allah’s statement in the sacred hadith: “My servant does not draw nearer to Me with anything more beloved to Me than that which I have made obligatory upon him.” (1) Thus, praying two obligatory units of prayer is more beloved to Allah than praying two voluntary units.
As for the rational evidence, Allah’s making an act obligatory indicates that it is more emphatically required, and that the legally responsible person is in greater need of it than of voluntary acts of worship.
Is there a distinction between what is recommended and what is prescribed by the sunnah?
The answer is that some scholars have distinguished between them, saying that what is recommended is that which is established by analogy, whereas what is prescribed by the sunnah is that which is established by the sunnah—that is, by textual evidence.
However, the correct view is that there is no difference between them; the matter is merely one of terminology. According to the Hanbalis, there is no distinction between them. Thus, there is no difference between saying, “It is recommended to perform ablution three times,” and saying, “It is sunnah to perform ablution three times.” This is merely a terminological convention. That is, if someone were to state in one of his works, “Whenever I use the expression ‘it is sunnah,’ I mean that which is established by the sunnah; and whenever I use the expression ‘it is recommended,’ I mean that which is established by analogy,” then consistently followed this convention, he would not be criticized for it.