Musar for Berakhot 12:2

We have set forth a little of the eminence of a man who is habituated to praying with a minyan, and the great increase of his mitzvoth and merits. The major thing here is that this mitzvah be a steady one, and not one that he slackens in. But if sometimes he performs it and sometimes slackens in it, G-d forbid, then he is in the class of (Vayikra 26:21): "But if you walk with Me by chance, etc." (see Rashi there). And thus have our sages of blessed memory said (Berachoth 6b), that when a man is accustomed to come to the house of study, and once does not come, the Holy One Blessed be He "inquires" after him as to why he has not come. And this is intimated in (Isaiah 50:10): "Who among you who fears the L-rd — who listens to the voice of His servant — has walked in the darkness, where it is not light for him?" (If he had gone to perform a mitzvah, it would have been light for him, but having gone on a mundane errand, it was not light for him) (Ibid.): "Let him trust in the name of the L-rd." Why has this befallen him" Because he should have trusted in the name of the L-rd and did not. R. Yochanan said; "When the Holy One Blessed be He comes to the synagogue and does not find ten men there, He becomes angry, viz. (Ibid. 2): 'Why, when I came, was there no man? when I called, was there no response?'" The intent is that even if a man were presented with an opportunity for profit at the time of his going to the synagogue, he should not pay heed to it, but trust in the name of the L-rd that what was set aside for him by Heaven will not be detracted from him. And, indeed, very often this is a test from Heaven for him. As our sages of blessed memory have said: "There is no man who is not subjected to tests. A rich man is tested; a poor man is tested, etc." And when a man reflects upon this, he sees this in his experience. He may sometimes stand a whole day in his shop and see very few customers, and when the time for the minchah prayer arrives [or on Sabbath eve before sunset], new customers come, whom he had never seen before, and beg him to sell to them — and all this, as a test, the Holy One Blessed be He testing him to see if his [Divine] service is dear to him [to be performed] with all of his heart and all of his soul.