Responsa על ברכות 12:1

They responded: "God loves the gates of Zion more than all the dwellings of Jacob." (Psalms 87:2) - God loves those gates distinguished by halacha (Berachot 8a:17). I did not understand this answer, and the next night I repeated the question, and asked them to give a clearer response. They then responded as they had done previously, and explained: 'God loves those gates distinguished by halacha' - when one makes a halachic innovation and has it rest on solid foundations. Such gates are beloved by the Great King more than all the dwellings of Jacob³Understood by the Talmud to refer to synagogues. , in which the other commandments are fulfilled. Anybody who thinks and reasons in complex areas of abstract and applied halacha is beloved and desired by the Supreme King. This is the meaning of the Talmudic statement "The reward of learning is for reasoning" (Berachot 6b:13). These words and thoughts are like precious stones in His eyes, and if for the sake of the loss of a coin or something of its value the Torah allowed work during the festival, how much more so may those who stand to lose these precious stones write them down permanently that they may be preserved. Those who write and seal such words will be rewarded - all this they responded to me in truth. And it seems to me that one's business correspondence, where one doesn't stand to lose anything, should not be written even in an abnormal way. But a letter in which one asks about the wellbeing of their friend, and informs them of news - this makes the person happy⁴This is the understanding of Rif Moed Katan 10b:4, contra the opinion of Rashi on Moed Katan 18b:5:3. For the sake of such happiness, the Sages permitted to write personal correspondence, because they demand wellbeing.