John Calvin on 1 Thessalonians 2:9

9 For ye remember. These things tend to confirm what he had stated previously — that to spare them he did not spare himself. He must assuredly have burned with a wonderful and more than human zeal, inasmuch as, along with the labor of teaching, he labors with his hand as an operative, with the view of earning a livelihood, and in this respect, also, refrained from exercising his right. For it is the law of Christ, as he also teaches elsewhere, (1 Corinthians 9:14) that every church furnish its ministers with food and other necessaries. Paul, therefore, in laying no burden upon the Thessalonians, does something more than could, from the requirements of his office, have been required from him. In addition to this, he does not merely refrain from incurring public expense, but avoids burdening any one individually. Farther, there can be no doubt, that he was influenced by some good and special consideration in thus refraining from exercising his right, “Entre les Thessaloniciens;” — “Among the Thessalonians.” for in other churches he exercised, equally with others, the liberty allowed him. “La liberte que Dieu donne;” — “The liberty that God gives.” He received nothing from the Corinthians, lest he should give the false apostles a handle for glorying as to this matter. In the mean time, he did not hesitate to ask “Il n’a point fait de conscience de prendre lors des autres Eglises;” — “He made no scruple to take at that time from other Churches.” from other churches, what was needed by him, for he writes that, while he bestowed labor upon the Corinthians, free of charge, he robbed the Churches that he did not serve. (2 Corinthians 11:8) See Calvin on the Corinthians, vol. 2, p. 347. Hence, although the reason is not expressed here, we may, nevertheless, conjecture that the ground on which Paul was unwilling that his necessities should be ministered to, was — lest such a thing should put any hindrance in the way of the gospel. For this, also, ought to be matter of concern to good pastors — that they may not merely run with alacrity in their ministry, but may, so far as is in their power, remove all hindrances in the way of their course.